KR101213347B1 - An Apparatus and Method for Preventing the Crystallization of a Solution in Absorption Type Cooler and Heater - Google Patents

Abstract

The present invention measures the measured temperature of the outlet concentrate of the low-temperature heat exchanger and compares it with the crystal temperature, and if the crystal is likely to be formed, the solution is heated and diluted by opening the determination valve and introducing a hot heavy solution. Disclosed is a solution determination preventing device and a solution determination preventing method of an absorption type cold and hot water machine, which can prevent the determination of.
The present invention comprises a high temperature regenerator which puts a low concentration absorption solution and heats it to heat the refrigerant to vaporize it into a medium concentration absorption solution; A low temperature regenerator for heating the medium absorbent solution using the heat of condensation of the vaporized refrigerant in the high temperature regenerator and vaporizing the refrigerant contained in the medium absorbent solution to produce a high concentration absorbent solution; A condenser for cooling the vaporized refrigerant separated in the high temperature regenerator and the low temperature regenerator to form a liquid refrigerant; An evaporator for evaporating the liquid refrigerant liquefied in the condenser to enable cooling through a cold water line; The vaporizing refrigerant evaporated in the evaporator is absorbed by a high temperature absorbing solution obtained in a low temperature regenerator to reduce the concentration, a high concentration of a portion of the high temperature medium concentration absorbing solution in the high temperature regenerator from the low temperature regenerator to the absorber It is characterized by providing a solution line connected with a high concentration absorption solution line to prevent crystallization by mixing with the absorption solution, and has a feature of the solution determination prevention device provided with a crystal check valve on the solution line.
In addition, the present invention comprises a first step of determining the crystal temperature according to the absorbent concentration ratio;
A second step of determining a measurement temperature by measuring the temperature of the high concentration absorbing solution at the outlet of the low temperature regenerator after the first step;
And a third step of opening a determination preventing valve provided on a solution line connected to a high temperature regenerator if the determination occurs after comparing the determination temperature with the measurement temperature.
When the determination valve is opened, the solution determination method is characterized by preventing the determination of the solution by mixing and diluting the hot medium absorbent solution of the high temperature regenerator with the high concentration absorbent solution from the low temperature regenerator.

Description

An Apparatus and Method for Preventing the Crystallization of a Solution in Absorption Type Cooler and Heater}

The present invention relates to a solution determination prevention device and a solution determination prevention method of an absorption type cold and hot water heater, and more particularly, by comparing the measurement temperature and the crystallization temperature of the high concentration absorption solution at the outlet of a low temperature heat exchanger, and then opening the determination prevention valve to open a high temperature medium concentration. By absorbing the absorbent solution, the high concentration absorbent solution may be heated and diluted to prevent the solution from being crystallized in advance.

In general, air conditioners are designed to maintain optimum temperature and humidity according to all climatic conditions and indoor environments, and humidifiers to maintain proper humidity, including cooling and heating devices that cool or warm indoor air. And a ventilator for exhausting indoor air to the outside.

Such an air conditioner may be classified into various types according to a refrigerant used. There is an absorption cold / hot water machine using water as a refrigerant.

Absorption chiller is a device that operates a cycle consisting of absorption solution / refrigerant using gas such as LPG and LNG as a heat source, and unlike the cold and hot water that uses electricity as energy source, it uses excessive heat energy in summer. It removes the load and is also used for cogeneration systems using waste heat.

In absorption type cold and hot water machine using water as a refrigerant, lithium bromide (LiBr) (absorption solution) is mainly used as an absorbent, and water and lithium bromide solution are heated using steam or hot water.

Referring to the conventional absorption cold and hot water machine in more detail through the drawings as follows.

As shown in FIG. 1, the main configuration of the conventional absorption type cold and hot water heater 1 includes a high temperature regenerator 10, a low temperature regenerator 20, a condenser 30, an evaporator 40, and an absorber 50. In addition, a high temperature heat exchanger 60 and a low temperature heat exchanger 70 are installed between the high temperature regenerator 10 and the absorber 50, and the solution from the absorber 50 is condenser 30 at the low temperature regenerator 20. Drain heat exchanger 80 is installed to pass through the refrigerant entering.

The high temperature regenerator 10 is heated by putting a lithium bromide solution, which is a low concentration absorption solution (diluent solution), and heated to vaporize the refrigerant (water) by the steam generated in the boiler 11 to form a medium concentration absorption solution.

In addition, the low temperature regenerator 20 heats the medium absorbent solution using the heat of condensation of the vaporized refrigerant in the high temperature regenerator 10 and vaporizes the refrigerant contained in the medium absorbent solution (heavy solution) to absorb the high concentration absorbent solution (a concentrated solution). )

In addition, the condenser 30 cools the vaporized refrigerant (water vapor) separated from the high temperature regenerator 10 and the low temperature regenerator 20 to form a liquid refrigerant (water).

In addition, the evaporator 40 allows the liquid refrigerant liquefied in the condenser 30 to be evaporated under vacuum to enable cooling through the cold water line 41.

In addition, the absorber 50 absorbs the vaporized refrigerant evaporated in the evaporator 40 in the high temperature absorbing solution obtained in the low temperature regenerator 20, thereby lowering the concentration.

In the conventional absorption type cold and hot water heater 1 having such a configuration, the absorbing solution is introduced into the high temperature regenerator 10 from the absorber 50, at which time the high temperature regenerator 10 is passed through the low temperature heat exchanger 70 and the high temperature heat exchanger 60. It is heated to and heated, and the rare solution becomes the medium concentration absorbing solution as the refrigerant vapor is separated.

The refrigerant vapor flows into the low temperature regenerator 20, and the medium concentration absorption solution entering the low temperature regenerator 20 from the high temperature regenerator 10 is heated in the low temperature regenerator 20 to further separate the refrigerant vapor into the high concentration absorption solution. At this time, the separated refrigerant vapor is introduced into the condenser (30).

The medium absorbing solution introduced into the low temperature regenerator 20 from the high temperature regenerator 10 is introduced through the high temperature heat exchanger 60.

In addition, the high concentration absorbing solution, which becomes high by vaporization in the low temperature regenerator 20, flows into the absorber 50 through the low temperature heat exchanger 70.

On the other hand, the refrigerant vapor introduced into the condenser 30 is condensed and becomes a liquid refrigerant and flows into the evaporator 40.

In the evaporator 40, the liquid refrigerant is dispersed, and the refrigerant vapor evaporated in the evaporator 40 is introduced into the absorber 50 and absorbed by the scattered absorbing solution, thereby lowering the concentration. The lowered absorbent solution is preheated while passing through the low temperature heat exchanger 70 and the high temperature heat exchanger 60 by the absorber pump 51 and introduced into the high temperature regenerator 10.

In the conventional absorption type cold / hot water machine 1 operated in such a cycle, the absorption of heat varies according to the concentration change of the lithium bromide solution, which is an absorption solution, and thus the lithium bromide solution should be prevented from crystallization.

If a crystal is formed, a phenomenon in which the pipe through which the absorbing solution passes passes may be clogged. In particular, a high concentration absorbent solution coming out of the outlet of the low temperature regenerator 20 may have a large crystal.

As shown in FIG. 2, the conventional absorption cold / hot water machine cannot be prevented in advance because a separate means for preventing the determination of the absorbing solution cannot be determined, and thus the absorber inlet solution temperature and the crystallization temperature are compared. It can be seen that a) overlaps each other in the region. By overlapping in this way, it becomes a condition where a decision can occur.

Furthermore, conventionally, when the solution temperature and the crystal temperature are different, that is, when the solution temperature is larger than the crystal temperature, the heat input is normally maintained, and when the solution temperature and the crystal temperature are the same or when the solution temperature approaches the crystal temperature, the system is maintained. In this case, the heat input is controlled to 0. The solution temperature and the crystal temperature are the same. There is a problem that takes time.

Accordingly, the present invention has been made to solve the conventional problems as described above, an object of the present invention is to mix a portion of the medium absorbent solution of the high temperature regenerator with a high concentration absorbent solution from the low temperature regenerator to prevent the determination of the solution I would have to.

The present invention for achieving the above object is a high-temperature regenerator which is put into a low concentration absorption solution, heated to vaporize to make a medium concentration absorption solution; A low temperature regenerator for heating the medium absorbent solution using the heat of condensation of the vaporized refrigerant in the high temperature regenerator and vaporizing the refrigerant contained in the medium absorbent solution to produce a high concentration absorbent solution; A condenser for cooling the vaporized refrigerant separated in the low temperature regenerator to form a liquid refrigerant; An evaporator for evaporating the liquid refrigerant liquefied in the condenser to enable cooling through a cold water line; The vaporized refrigerant evaporated in the evaporator is absorbed in a high temperature absorption solution obtained in a low temperature regenerator made of an absorber to lower the concentration,

A solution line is connected to a high concentration absorbing solution line to prevent crystallization by mixing a portion of the high temperature medium absorbing solution in the high temperature regenerator with a high concentration absorbing solution going from the low temperature regenerator to the absorber, and on this solution line Determination valve is installed.

In addition, the present invention comprises a first step of determining the crystal temperature according to the absorbent concentration ratio;

A second step of determining a measurement temperature by measuring the temperature of the high concentration absorbing solution at the outlet of the low temperature regenerator after the first step; And a third step of opening a determination preventing valve provided on a solution line connected to a high temperature regenerator if the determination occurs after comparing the determination temperature with the measurement temperature.

In the case of opening the crystal check valve, it is a crystal prevention method which prevents the determination of the solution by mixing and diluting the high temperature medium concentration absorbing solution of the high temperature regenerator with the high concentration absorbing solution from the low temperature regenerator.

In addition, the crystal check valve is opened when the difference between the measured temperature and the crystal temperature is less than 2, and closed when the difference between the measured temperature and the crystal temperature exceeds 3.

The third step includes a fourth step of providing a heat input restriction condition when it is difficult to prevent the determination of the solution by the determination check valve.

In addition, the difference between the solution temperature and the crystal temperature is to reduce the heat input in the range of 5 to -5.

In addition, when the solution temperature and the crystal temperature become the same, the heat input amount is set to 95%.

As described above, the present invention can prevent the crystals from occurring in the absorbent solution in advance in accordance with the opening of the crystal prevention valve in the absorption type cold and hot water machine, thereby improving the system performance.

1 is a block diagram of a conventional absorption chiller.
Figure 2 is a graph comparing the absorber inlet solution temperature and the crystallization temperature according to the conventional absorption chiller.
3 is a block diagram of the absorption chiller of the present invention.
Figure 4 is a graph showing the crystal temperature according to the concentration of the absorbing solution to be applied to the absorption chiller of the present invention.
Figure 5 is a graph comparing the absorber inlet solution temperature and the crystallization temperature according to the absorption chiller of the present invention.
Figure 6 is a graph showing the heat input according to the difference between the solution temperature and the crystal temperature for applying to the present invention.
7 is a graph comparing the absorber inlet solution temperature and the crystallization temperature when the heat input minimum control is applied by the absorption chiller according to the present invention.
8 is a graph comparing the absorber inlet solution temperature and the crystallization temperature when the heat input limit condition is applied by the absorption type cold and hot water heater according to the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

As shown in FIG. 3, the high temperature regenerator 10, the low temperature regenerator 20, the condenser 30, the evaporator 40, and the absorber 50 are formed as in the related art.

The high temperature heat exchanger 60 and the low temperature heat exchanger 70 are installed between the high temperature regenerator 10 and the absorber 50, and the solution from the absorber 50 is transferred from the low temperature regenerator 20 to the condenser 30. A drain heat exchanger 80 is installed to allow the refrigerant to enter therethrough.

The high temperature regenerator 10 is heated by putting a lithium bromide solution, which is a low concentration absorption solution (diluent solution), and heated to vaporize the refrigerant (water) by the steam generated in the boiler 11 to form a medium concentration absorption solution.

In addition, the low temperature regenerator 20 heats the medium absorbent solution using the heat of condensation of the vaporized refrigerant in the high temperature regenerator 10 and vaporizes the refrigerant contained in the medium absorbent solution (heavy solution) to absorb the high concentration absorbent solution (a concentrated solution). )

In addition, the condenser 30 cools the vaporized refrigerant (water vapor) separated from the high temperature regenerator 10 and the low temperature regenerator 20 to form a liquid refrigerant (water).

In addition, the evaporator 40 allows the liquid refrigerant liquefied in the condenser 30 to be evaporated under vacuum to enable cooling through the cold water line 41.

In addition, the absorber 50 absorbs the vaporized refrigerant evaporated in the evaporator 40 in the high temperature absorbing solution obtained in the low temperature regenerator 20, thereby lowering the concentration.

Here, the present invention is a separate solution line to mix a portion of the high temperature medium concentration absorbing solution in the high temperature regenerator 10 with the high concentration absorbing solution going from the low temperature regenerator 20 to the absorber 50 to prevent crystallization (101) is provided, and the crystal prevention valve (100) is provided on the solution line (101).

Therefore, if there is a possibility that crystals may occur in the high concentration absorbing solution flowing from the low temperature regenerator 20 to the absorber 50, the crystal check valve 100 may be opened to open the solution line 101 from the high temperature regenerator 10. The medium concentration absorbing solution may be sent to the absorber 50 through the low temperature heat exchanger 70 in a state where it is mixed with the high concentration absorbing solution line 21 of the low temperature regenerator 20 to prevent the determination of the solution in advance. It is.

In addition, the present invention provides a method for preventing solution determination by determining the possibility of crystallization of a solution (absorbent solution), as shown in FIG. A first step of determining the crystal temperature according to the concentration ratio of the absorbent liquid through a graph showing the relationship between the crystal temperature according to the present invention; A second step of determining a measurement temperature by measuring the temperature of the high concentration absorbing solution at the outlet of the low temperature regenerator after the first step; And a third step of opening a determination preventing valve provided on a solution line connected to a high temperature regenerator if the determination occurs after comparing the determination temperature with the measurement temperature.

In the case of opening the crystal check valve, it is possible to provide a solution preventing method for preventing the determination of a solution by mixing and diluting a high temperature medium concentration absorbing solution of a high temperature regenerator with a high concentration absorbing solution from a low temperature regenerator.

In addition, when the determination prevention valve 100 is opened and closed, when the measurement temperature (T1) -determination temperature (TC) <2 in the absorption type cold and hot water system, the determination prevention valve 100 is opened and the measurement temperature (T1) -determination temperature If (TC)> 3, the determination valve 100 is closed.

FIG. 5 is a graph comparing the absorber inlet solution temperature and the crystallization temperature when the crystal prevention valve 100 according to the present invention is provided. As a conventional condition, FIG. 5 is a dotted line at a central position (about 3,500 sec) on the horizontal axis. It can be seen that the crystallization temperature diagram is formed with a gap with the absorber inlet solution temperature diagram in the vicinity of the vertical line (a).

In other words, the formation of the crystallization temperature line with a gap between the absorber inlet solution temperature line means that crystallization is prevented in advance.

On the other hand, in a situation where it is difficult to prevent the determination of the solution only by the determination prevention valve 100, for example, the solution in the absorber 50 does not become a normal low concentration solution (solution solution) due to the abnormality of the absorber 50. In the case where the high temperature regenerator 10 flows, even after the determination prevention valve 100 is opened, a time point at which a determination is not properly prevented may occur.

In this case, therefore, the heat recovery limit can shorten the risk of non-crystallization of the solution and reduce the return time to the normal system.

In other words, the solution determination prevention method according to the present invention includes a fourth step of providing a heat input limit condition when it is difficult to prevent the determination of the solution by the determination check valve in the third step.

Specifically, as shown in Fig. 6, as a graph showing the relationship between the heat input (heat input by the heating source in the high temperature regenerator 10) for the difference between the solution temperature (measurement temperature) and the crystal temperature; On the basis of the zero of the horizontal axis (difference between solution temperature and crystal temperature), the negative zone means that the crystal temperature is higher than the solution temperature, and the positive zone means that the solution temperature is higher than the crystal temperature. As the calorific value, the difference between the solution temperature and the crystallization temperature is continuously decreased until it is 5 degrees Celsius or less, and when the difference between the solution temperature and the crystallization temperature is more than 5 degrees, it becomes constant without changing the heat input amount. have.

In other words, when the crystal is generated when there is no difference between the solution temperature and the crystal temperature, the crystal is generated, but unlike the conventional method (with the heat input value of 0), the heat input amount is set to 95% and the time when the crystal is generated (solution temperature). And when the difference between the crystallization temperature is 0 degrees or less and -5 degrees), since the possibility of crystallization increases as the amount of heat input decreases, the crystallization valve 100 is opened to dilute the solution to prevent crystallization. will be.

In Fig. 6, the ratio of the rated heat input of each absorption cold / hot water heater to the reference, the heat input amount of 100% indicates a normal solution state, when 95%, it is the time to open the crystal check valve 100, When reducing calories, reduce the amount of vapor from the solution. The effect of diluting the solution concentration continuously can be obtained.

Therefore, in the solution crystal prevention method of the present invention, by partially limiting the heat input while opening and closing the crystal prevention valve through the difference between the solution temperature and the crystal temperature, it is possible to obtain the effect of significantly reducing the normal return time of the absorption chiller system. . This can be easily seen even with reference to FIGS. 7 and 8.

In other words, FIG. 7 is a graph in which only the check valve 100 is applied and does not reflect the heat input amount, and is basically a vertical line (a) of a dotted line showing a determination state at the same time as in FIGS. 2 and 5. ) Shows that a gap is formed.

In addition, as shown in FIG. 8, even when the determination valve 100 and the heat input restriction condition in FIG. 6 are applied, it can be seen that a gap is formed in the vertical line a of the dotted line. Therefore, it is basically possible to prevent the determination of the solution according to the operation of the determination prevention valve 100.

Moreover, when the time to prevent the determination of the solution by the determination valve 100 is difficult, that is, in the case of the determination prevention danger interval (range between the vertical line (a) and the vertical line (b)), Figures 7 and 8 In comparison, it can be seen that the time to the vertical line b of the second dotted line in FIG. 8 is shorter than in FIG. 7.

In FIGS. 7 and 8, after the vertical line (b) of the second dotted line, it can be seen that a gap is formed between the solution temperature and the crystallization temperature, and this indicates that the solution is returned to the normal state while the solution is prevented from being crystallized.

Therefore, when the condition of FIG. 8 is compared to the condition of FIG. 7, it can be seen that the crystal generation interval occurring after the determination prevention by the determination prevention valve 100 is short.

While the invention has been described for the embodiments of the invention based on the accompanying drawings for convenience, various modifications and variations are possible within the scope of the technical idea of the present invention, such variations and modifications are claims of the present invention Inclusion within is self-evident.

1: Absorption chiller
10: high temperature regenerator
11: Boiler
20: low temperature regenerator
21: High concentration solution line
30: condenser
40: evaporator
41: cold water line
50: absorber
51: absorber pump
52: solution cooling absorber
60: high temperature heat exchanger
70: low temperature heat exchanger
80: drain heat exchanger
100: Determination check valve
101: solution line

Claims (6)

A high temperature regenerator which puts a low concentration absorption solution into a medium concentration absorption solution by heating and vaporizing it;
A low temperature regenerator for heating the medium absorbent solution using the heat of condensation of the vaporized refrigerant in the high temperature regenerator and vaporizing the refrigerant contained in the medium absorbent solution to produce a high concentration absorbent solution;
A condenser for cooling the vaporized refrigerant separated in the low temperature regenerator to form a liquid refrigerant;
An evaporator for evaporating the liquid refrigerant liquefied in the condenser to enable cooling through a cold water line;
The vaporized refrigerant evaporated in the evaporator is absorbed in a high temperature absorption solution obtained in a low temperature regenerator made of an absorber to lower the concentration,
A solution line is connected to a high concentration absorbing solution line to prevent crystallization by mixing a portion of the high temperature medium absorbing solution in the high temperature regenerator with a high concentration absorbing solution going from the low temperature regenerator to the absorber, and on this solution line Install a check valve
The determination prevention valve is a liquid crystal prevention device of the absorption type cold and hot water heater, characterized in that to open when the difference between the measured temperature and the crystal temperature of the solution is less than 2, and closed when the difference between the measured temperature and the crystal temperature exceeds 3. delete A first step of determining a crystal temperature according to the absorption liquid concentration ratio;
A second step of determining a measurement temperature by measuring the temperature of the high concentration absorbing solution at the outlet of the low temperature regenerator after the first step;
A third step of opening a determination preventing valve provided on a solution line connected to a high temperature regenerator if the determination temperature is compared with the measurement temperature after the second step;
In the third stage, when it is difficult to prevent the determination of the solution by the determination valve, including the fourth stage to give a heat input restriction condition,
In the case of opening the determination valve, it is possible to prevent the determination of the solution by mixing and diluting the hot medium absorbent solution of the high temperature regenerator with the high concentration absorbent solution from the low temperature regenerator.
When the solution temperature and the crystal temperature is the same, the heat input amount of the liquid crystal absorption method of the absorption cold and hot water heater, characterized in that for setting the 95%.
The method according to claim 3,
The determination preventing valve is opened when the difference between the measured temperature and the crystal temperature of the solution is less than 2, and closed when the difference between the measured temperature and the crystal temperature of the solution is greater than three.
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