KR102206209B1 - Absorption chiller - Google Patents

Abstract

It is an absorption chiller equipped with an evaporator, an absorber, a low pressure regenerator, a high pressure regenerator, an auxiliary absorber, an auxiliary regenerator, a condenser, and a solution pump. The evaporator and the absorber communicate with the gas phase, and the low pressure regenerator and the auxiliary absorber are , The gas phase part communicates, the high-pressure regenerator and the auxiliary regenerator and the condenser communicate with the gas-phase part, and the solution pipe from the absorber to the high-pressure regenerator has a branch, and a solution pipe to the low-pressure regenerator is connected to the branch part. The pump is provided in a solution pipe from the absorber to the branch, and the solution pipe from the high pressure regenerator to the absorber has a confluence part connected to the solution pipe to the low pressure regenerator. Thereby, in an absorption chiller in which a single-effect cycle and a two-stage absorption cycle are combined, heat can be recovered from one heat source at about 90°C until a low temperature is reached to supply cold heat, and the low pressure regenerator can be downsized. In addition, a degree of freedom can be given to the arrangement of each heat exchanger, a solution pump can be reduced, and power consumption can be reduced.

Description

Absorption chiller

The present invention relates to an absorption refrigerator.

Since the absorption chiller can be thermally driven, it is possible to supply cold heat by using hot water produced as an array as a driving heat source. In one short-effect cycle, the regenerator can supply cold heat of about 7°C using hot water of about 90°C as the driving heat source.

In Patent Document 1, it is described that the regenerator has two two-stage absorption cycles, and that cold heat can be supplied by using hot water having a temperature lower than that of the single effect cycle as a driving heat source.

In addition, Patent Document 2 describes an absorption refrigerator in which a single-effect cycle and a two-stage absorption cycle are combined. This consists of a single-effect cycle and an auxiliary cycle, and a high-pressure regenerator and a low-pressure regenerator are provided on the short-effect cycle side, and the entire amount of the solution is circulated in the order of an absorber, a high pressure regenerator, a low pressure regenerator, and an absorber. In addition, the auxiliary cycle side is composed of an auxiliary absorber and an auxiliary regenerator, the gas phase portion of the auxiliary absorber communicates with the low pressure regenerator, and the gas phase portion of the auxiliary regenerator communicates with the high pressure regenerator and the gas phase portion of the condenser. In Patent Document 2, hot water of a driving heat source can be used from a temperature required for a single-effect cycle to a temperature required for a two-stage absorption cycle.

Japanese Patent Publication No. 2004-211979 (Fig. 6) Korean Unexamined Japanese Patent No. 10-2011-0014376 (Fig. 2)

In order to save energy, it is an effective means to generate and reuse as much cold heat as possible from one heat source. As a means for this, it is conceivable to use, for example, hot water of about 90° C. as a driving heat source for a single-effect cycle, and then use the warm water, which has cooled down, as a driving heat source for a two-stage absorption cycle. However, in this case, two absorption chillers with different cycle configurations are required, and two piping systems for cold water and cooling water are required, so the piping configuration becomes complicated, and the installation area increases and the cost increases. Further, in the case of using two absorption refrigerators, the number of solution pumps and refrigerant pumps is almost doubled, so that the amount of power consumption increases.

In the technique of Patent Document 2, a cycle corresponding to the above problem is achieved with one absorption chiller. However, in the technique of Patent Document 2, the entire amount of the solution discharged from the absorber on the side of the short-effect cycle is introduced into a high-pressure regenerator comprising a falling liquid film type heat exchanger, and the entire amount of the solution exiting the high-pressure regenerator is a low-pressure liquid film heat exchanger. It is becoming a series flow flowing into the regenerator. Therefore, the solution concentrated in the high pressure regenerator flows into the low pressure regenerator. For this reason, the solution concentrated in the low pressure regenerator has the highest concentration. If the solution is at the same pressure, the temperature of the solution with the higher concentration increases, and in the low pressure regenerator, the concentration becomes higher than that of the solution concentrated in the high pressure regenerator, so that the temperature difference with the driving heat source decreases, and the required heat transfer area increases.

In the case of series flow, when the heat exchanger sizes are different in the high-pressure regenerator and the low-pressure regenerator, it cannot be adjusted to a suitable solution flow rate for each. In particular, in the case of using a falling liquid film type heat exchanger in a high-pressure regenerator and a low-pressure regenerator, if a heat exchanger size suitable for the dispersion density of the solution is desired, the heat exchanger size is fixed and the degree of freedom of arrangement of the device decreases.

In addition, on the short-effect cycle side, it is conceivable that the amount of power consumption of the solution pump increases because a solution pump is installed at each outlet in order to circulate the entire amount of the solution in the order of the absorber, the high-pressure regenerator, and the low-pressure regenerator. have. In the absorption chiller, in order to achieve the advantage of thermal driving, reduction of the amount of power consumption required for driving the pump is one of effective means.

An object of the present invention is to provide an absorption chiller in which a single-effect cycle and a two-stage absorption cycle are combined, recovering heat from a single heat sink at about 90°C until reaching a low temperature and supplying cold heat, and a low-pressure regenerator The purpose is to reduce the size of each heat exchanger, to give a degree of freedom to the arrangement of each heat exchanger, and to optimize the number of solution pumps.

The absorption chiller of the present invention includes an evaporator, an absorber, a low-pressure regenerator, a high-pressure regenerator, an auxiliary absorber, an auxiliary regenerator, a condenser, and a solution pump, and the evaporator and the absorber communicate with a gas phase unit, and a low-pressure regenerator. And the auxiliary absorber communicates with the gas phase part, the high pressure regenerator and the auxiliary regenerator and the condenser communicate with the gas phase part, and the solution pipe from the absorber to the high pressure regenerator has a branch, and in this branch, a solution pipe directed to the low pressure regenerator It is connected, and the solution pump is provided in a solution pipe from the absorber to the branch, and the solution pipe from the high pressure regenerator to the absorber has a confluence part connected to the solution pipe from the low pressure regenerator.

According to the present invention, in an absorption refrigerator in which a single-effect cycle and a two-stage absorption cycle are combined, one driving heat source of about 90°C can be recovered to a lower temperature to supply cold heat, and the low pressure regenerator can be downsized. .

Further, according to the present invention, while providing a degree of freedom in arranging devices, it is possible to reduce the amount of solution pumps and reduce power consumption.

1 is a schematic configuration diagram showing an absorption refrigerator of an embodiment.
Fig. 2 is a During diagram showing the absorption cycle of the absorption refrigerator according to the embodiment.

[0001] The present invention relates to an absorption chiller comprising two independent solution cycles by supplying a heat source medium to three regenerators.

Hereinafter, specific embodiments of the present invention will be described with reference to the drawings. In addition, in each drawing, the part denoted with the same reference|symbol represents the same or equivalent part.

Example

1 is a cycle diagram showing an absorption chiller of an embodiment.

2 is a graph showing the cycle state of the present invention in a During diagram composed of an isometric concentration line of a solution. Solution temperature is taken on the horizontal axis and pressure is taken on the vertical axis.

E, A, LG, HG, AA, AG, and C of FIG. 1 and E, A, LG, HG, AA, AG and C of FIG. 2 denote the same part.

First, the cycle flow of the absorption refrigerator according to the present invention will be described.

The absorption chiller consists of a short-effect cycle side and an auxiliary cycle side, and the solution circulates independently in each cycle. The short-effect cycle side is a heat exchanger of the evaporator 1, the absorber 9, the low pressure regenerator 22, the high pressure regenerator 33, the condenser 40, the low temperature solution heat exchanger 55, and the high temperature solution heat exchanger 56. A urea, refrigerant pump 6, solution pumps 14, 30, and the like are provided. The auxiliary cycle side is provided with an auxiliary absorber 16, an auxiliary regenerator 44, a heat exchanger element of the medium temperature solution heat exchanger 57, solution pumps 29, 54, and the like.

Next, the operation of the short-effect cycle side will be described.

In the evaporator 1, the refrigerant stored in the lower portion of the evaporator 1 by the refrigerant pump 6 is guided to the dispersing device 2 through the refrigerant pipe 7 and is dispersed outside the heat transfer pipe of the heat exchanger 3. The scattered refrigerant is heated with cold water flowing through the heat transfer pipe of the heat exchanger 3 to become partially refrigerant vapor, and is guided to the absorber 9 through the eliminator 8. At this time, the cold water flowing in the heat transfer pipe of the heat exchanger 3 is cooled by using the latent heat of evaporation when the refrigerant evaporates. Cold water pipes 4 and 5 are connected to the heat exchanger 3 to pass cold water for supplying cold heat to the load side.

In the absorber 9, the solution concentrated in the low pressure regenerator 22 and the high pressure regenerator 33 is dispersed from the dispersing device 10 to the outside of the heat transfer pipe of the heat exchanger 11. The dispersed solution absorbs the refrigerant vapor from the evaporator 1, the concentration decreases, and after passing through the low temperature solution heat exchanger 55 with the solution pump 14 installed in the middle of the solution pipe 15, the branch point A Branching from the (branching part), one side is guided to the low pressure regenerator 22 through the flow rate adjustment valve 32 (flow rate adjustment means) of the solution pipe 31. The other solution branched at the branch point A is guided to the high-pressure regenerator 33 through the hot solution heat exchanger 56. Cooling water is passed through the heat transfer pipe of the heat exchanger 11 of the absorber 9 in order to remove the heat of absorption generated when the solution absorbs the refrigerant vapor. Cooling water pipes 12 and 13 are connected to the heat exchanger 11.

In the low-pressure regenerator 22, the solution whose concentration is reduced in the absorber 9 is dispersed from the dispersing device 23 to the outside of the heat transfer tube of the heat exchanger 24. The dispersed solution is heated with a heat source medium flowing through the heat transfer pipe of the heat exchanger 24 and separated into a concentrated solution and refrigerant vapor. The concentrated solution merges with the solution from the high-pressure regenerator 33 at the confluence point B (consolidation part) through the solution piping 27. The refrigerant vapor is guided to the auxiliary absorber 16 on the auxiliary cycle side through the eliminator 21. Heat source medium pipes 25 and 26 are connected to the heat exchanger 24 of the low pressure regenerator 22.

In the high-pressure regenerator 33, the concentration decreases in the absorber 9, and the low-temperature solution heat exchanger 55 and the high-temperature solution heat exchanger 56 reduce the concentration. The heated solution is spread out of the heat transfer tube of the heat exchanger 35 from the spreading device 34. The dispersed solution is heated with a heat source medium flowing through the heat transfer pipe of the heat exchanger 35 and separated into a concentrated solution and refrigerant vapor. The concentrated solution is guided to the confluence point B through a high-temperature solution heat exchanger 56 installed in the middle of the solution pipe 49. The concentrated solution from the low pressure regenerator 22 and the high pressure regenerator 33 joined at the confluence point B is boosted by the solution pump 30 and guided to the absorber 9 through the low temperature solution heat exchanger 55. The refrigerant vapor separated from the concentrated solution in the high pressure regenerator 33 is guided to the condenser 40 through the baffle 39. Heat source medium pipings 36 and 37 are connected to the heat exchanger 35 of the high pressure regenerator 33.

In the condenser 40, the refrigerant vapor separated from the solution concentrated in the high-pressure regenerator 33 and the auxiliary regenerator 44 is cooled with cooling water flowing in the heat transfer pipe of the heat exchanger 41, and condensed and liquefied. The condensed and liquefied refrigerant is guided to the evaporator 1 through the refrigerant pipe 50. Cooling water pipes 42 and 43 are connected to the heat exchanger 41.

Next, the operation on the auxiliary cycle side will be described.

In the auxiliary absorber 16, the solution concentrated in the auxiliary regenerator 44 is spread out of the heat transfer tube of the heat exchanger 18 from the dispersing device 17. The dispersed solution absorbs the refrigerant vapor from the low-pressure regenerator 22 of the short-effect side cycle and decreases in concentration, and then the medium temperature solution heat exchanger 57 is connected to the solution pump 29 installed in the middle of the solution pipe 28. After passing, it is led to the auxiliary regenerator 44. Cooling water is passed through the heat transfer pipe of the heat exchanger 18 of the auxiliary absorber 16 to remove the absorption heat generated when the solution absorbs the refrigerant vapor. Cooling water pipes 19 and 20 are connected to the heat exchanger 18.

In the auxiliary regenerator 44, the solution whose concentration is reduced in the auxiliary absorber 16 is dispersed from the dispersing device 45 to the outside of the heat transfer tube of the heat exchanger 46. The dispersed solution is heated with a heat source medium flowing through the heat transfer pipe of the heat exchanger 46 and separated into a concentrated solution and refrigerant vapor. The concentrated solution is guided to the auxiliary absorber 16 through the medium temperature solution heat exchanger 57 through the solution pump 54 installed in the middle of the solution pipe 51. The refrigerant vapor separated from the concentrated solution is guided to the condenser 40 through the baffle 52. Heat source medium pipings 47 and 48 are connected to the heat exchanger 46 of the auxiliary regenerator 44.

The heat source medium is passed through the heat exchanger 35 of the high pressure regenerator 33, the heat exchanger 24 of the low pressure regenerator 22, and the heat exchanger 46 of the auxiliary regenerator 44 in that order. At this time, as shown in FIG. 2, the heat source medium is from a temperature higher than the solution temperature at the outlet of the high pressure regenerator 33 (about 90°C) to a temperature close to the solution temperature at the outlet of the auxiliary regenerator 44 (about 60°C). You can use up to.

In addition, in the present embodiment, as shown in FIG. 1, the refrigerant in the evaporator 1 is an absorber 9, a low pressure regenerator 22, a high pressure regenerator 33 and an auxiliary absorber 16, and an auxiliary regenerator 44. In ), the solution is used as a falling liquid film type heat exchanger in which the solution is dispersed from the dispersing device in the upper part of each heat exchanger.

As described above, in the configuration of the present invention, the low pressure regenerator 22 on the side of the short effect cycle and the gas phase part of the auxiliary absorber 16 on the side of the auxiliary cycle are communicated, and the high pressure regenerator 33 and the condenser 40 on the side of the short effect cycle are connected. ) And the gas phase part of the auxiliary regenerator 44 on the side of the auxiliary cycle, the single effect cycle and the two-stage absorption cycle can be combined and operated. Further, in this embodiment, an aqueous lithium bromide solution is used as the solution (absorbent), and water is used as the refrigerant.

Next, the configuration and effect according to the present invention will be described in FIGS. 1 and 2.

After passing through the low temperature solution heat exchanger 55, the solution discharged from the absorber 9 is branched at the branch point A. Thereby, as also shown in FIG. 2, the solution having a low concentration from the absorber 9 can be introduced into the low pressure regenerator 22. That is, the temperature of the solution to be introduced into the low pressure regenerator 22 can be lowered by a lower concentration than the outlet of the high pressure regenerator 33. Therefore, the temperature difference with the driving heat source temperature for driving the low pressure regenerator 22 can be made large, and the heat transfer area can be reduced as the temperature difference increases.

Further, by branching the solution from the absorber 9 at the branch point A, the amount of circulation in the high-temperature solution heat exchanger 56 can be reduced compared to the amount of circulation from the absorber 9. Accordingly, the size of the high-temperature liquid heat exchanger 56 can be reduced in accordance with the amount of circulation, and the sensible heat loss of the solution can be reduced, and the efficiency of the absorption refrigerator can be improved. In addition, the low-pressure regenerator 22 and the high-pressure regenerator 33 are configured to be able to adjust the distribution amount of the solution by a flow control valve 32 provided in the middle of the solution pipe 31 connected to the low pressure regenerator 22. Thereby, since the amount of dispersion of the solution to the low pressure regenerator 22 and the high pressure regenerator 33 can be arbitrarily adjusted, when determining the arrangement of the equipment, the size of the heat exchangers 24 and 35 can be adjusted within the range in which the amount of dispersion can be adjusted. It can be set freely.

Further, the solution concentrated in the low pressure regenerator 22 and the high pressure regenerator 33 is joined at the confluence point B, and a solution pump 30 is disposed between the confluence point B and the low temperature solution heat exchanger 55. Thereby, the solution from the high-pressure regenerator 33 uses the liquid head of the solution stored in the solution pump 30 and the high-pressure regenerator 33, and the in-flight pressure difference between the low-pressure regenerator 22 and the solution pump 30. The solution from the low pressure regenerator 22 can be press-fitted into the solution pump 30 using the solution pump 30 and the liquid head of the solution stored in the low pressure regenerator 22 while being press-fitted into the solution. Thereby, the solution pump 30 can guide the solution from the high pressure regenerator 33 and the low pressure regenerator 22 to the absorber 9. That is, since the solution of the low-pressure regenerator 22 and the high-pressure regenerator 33 can be handled by one of the solution pump 30, it is possible to reduce the cost and power consumption.

In the above-described embodiment, a configuration in which a falling liquid film heat exchanger is incorporated was described, but the embodiment of the present invention is not limited to this, and heat is recovered from one heat sink until it reaches a low temperature. From the viewpoint, the effect of the present invention can be obtained also in a configuration in which a flooded heat exchanger is incorporated. In addition, in the above-described embodiment, a flow adjustment means having a flow adjustment valve provided in a solution flow path branched and directed to the low pressure regenerator was described, but the embodiment of the present invention is not limited to this, and the solution flow path toward the high pressure regenerator It may be a configuration in which a flow rate adjustment valve is provided, or a configuration in which an appropriate flow path resistance previously set is provided in the two solution flow paths on the downstream side of the branch portion without providing a valve.

1: evaporator
2, 10, 17, 23, 34, 45: scattering device
3, 11, 18, 24, 35, 41, 46: heat exchanger
4, 5: cold water piping
6: refrigerant pump
7, 50: refrigerant piping
8, 21: Eliminator
9: absorber
12, 13, 19, 20, 42, 43: cooling water piping
14, 29, 30, 54: solution pump
15, 27, 28, 31, 49, 51: solution piping
16: auxiliary absorber
22: low pressure regenerator
25, 26, 36, 37, 47, 48: heat source medium piping
32: flow adjustment valve
33: high pressure regenerator
39, 52: baffle
40: condenser
44: auxiliary player
55: low temperature solution heat exchanger
56: hot solution heat exchanger
57: medium temperature solution heat exchanger

Claims (7)

Equipped with an evaporator, an absorber, a low pressure regenerator, a high pressure regenerator, an auxiliary absorber, an auxiliary regenerator, a condenser, and a solution pump,
The evaporator and the absorber are in communication with a vapor phase unit,
The low pressure regenerator and the auxiliary absorber are in communication with the gas phase unit,
The high-pressure regenerator and the auxiliary regenerator and the condenser are in communication with a gas phase unit,
The solution pipe from the absorber to the high-pressure regenerator has a branch, and a solution pipe to the low-pressure regenerator is connected to the branch,
The solution pump is provided in the solution pipe from the absorber toward the branch,
The solution pipe from the high pressure regenerator toward the absorber has a confluence part connected to the solution pipe from the low pressure regenerator,
A solution pump is provided in the solution pipe from the confluence portion toward the absorber. The absorption type refrigerator according to claim 1, wherein a flow rate adjustment means is provided in the solution pipe from the branch to the low pressure regenerator. The absorption chiller according to claim 1 or 2, wherein the evaporator, the absorber, the low pressure regenerator, the high pressure regenerator, the auxiliary absorber and the auxiliary regenerator have a falling liquid film heat exchanger. delete The absorption chiller according to claim 1 or 2, wherein the solution pipe from the absorber toward the branch portion and the solution pipe from the confluence portion toward the absorber to heat exchange are provided. The absorption chiller according to claim 1 or 2, wherein the solution pipe from the high-pressure regenerator toward the confluence part and the solution pipe from the branch part toward the high-pressure regenerator to heat exchange are provided. The absorption chiller according to claim 1 or 2, wherein a medium temperature solution heat exchanger is provided in which a solution pipe from the auxiliary absorber to the auxiliary regenerator and a solution pipe from the auxiliary regenerator to the auxiliary absorber perform heat exchange.

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