WO2018056024A1

WO2018056024A1 - Absorption refrigerator

Info

Publication number: WO2018056024A1
Application number: PCT/JP2017/031613
Authority: WO
Inventors: 浩伸川村; 藤居　達郎; 武田　伸之
Original assignee: 日立ジョンソンコントロールズ空調株式会社
Priority date: 2016-09-23
Filing date: 2017-09-01
Publication date: 2018-03-29
Also published as: JP6632951B2; KR20180051566A; CN108139126B; KR102017436B1; CN108139126A; JP2018048778A

Abstract

Provided is an absorption refrigerator with a configuration in which a single-effect cycle is combined with an auxiliary cycle, wherein the amount of solution retained can be reduced. An absorption refrigerator 100 comprises an evaporator 1, an absorber 9, a low-pressure regenerator 22, a high-pressure regenerator 33, an auxiliary absorber 16, an auxiliary regenerator 44, a condenser 41, and a solution pump 30. Solution piping 49 for a solution to flow from the high-pressure regenerator 33 to the absorber 9 has a junction B that is connected to solution piping 27 for a solution to flow from the low-pressure regenerator 22. The solution pump 30 is provided in the solution piping 49 from the junction B to the absorber 9. The bottom face 101 of the high-pressure regenerator 33 is disposed in a position higher than the bottom face 102 of the low-pressure regenerator 22.

Description

Absorption refrigerator

The present invention relates to an absorption refrigerator.

Since the absorption refrigerator can be driven by heat, cold water can be supplied using hot water generated as exhaust heat as a driving heat source. In a single effect cycle with one regenerator, cold water of about 7 ° C. can be supplied using hot water of about 90 ° C. as a driving heat source. Patent Document 1 describes that the regenerator is an absorption refrigerator having two two-stage absorption cycles, and cold water can be supplied using hot water having a temperature lower than that of an absorption refrigerator having a single effect cycle as a driving heat source. .

Patent Document 2 describes an absorption refrigerator that combines a single effect cycle and an auxiliary cycle (two-stage absorption cycle). This is a series flow in which a high-pressure regenerator and a low-pressure regenerator are provided on the single effect cycle side, and the entire amount of the solution is circulated in the order of the absorber, the high-pressure regenerator, the low-pressure regenerator, and the absorber. The auxiliary cycle side is composed of an auxiliary absorber and an auxiliary regenerator. The gas phase part of the auxiliary absorber communicates with the low pressure regenerator, and the gas phase part of the auxiliary regenerator is the gas phase part of the high pressure regenerator and the condenser. The structure communicated with is described. In Patent Document 2, it is assumed that hot water of a driving heat source can be used from one temperature required for an absorption refrigerator of a single effect cycle to a temperature required for an absorption refrigerator of a two-stage absorption cycle in one absorption refrigerator.

JP 2004-211979 A (FIG. 6) Korean Published Patent No. 10-10067241 (FIG. 2)

In order to save energy, it is an effective means to generate more cold heat from one exhaust heat source and reuse it. As a means for that, for example, hot water of about 90 ° C. is used as a driving heat source for an absorption refrigerator of a single effect cycle, and hot water whose temperature has subsequently decreased is used as a driving heat source of an absorption refrigerator of a two-stage absorption cycle. It is possible. However, in this case, two absorption refrigerators having different cycle configurations are required, and two piping systems for chilled water and cooling water are required, which complicates the piping configuration and increases the installation area and costs. Become. Furthermore, with two absorption refrigerators, the number of solution pumps and refrigerant pumps almost doubles, increasing the amount of power consumption and also doubling the amount of solution and the amount of refrigerant.

On the other hand, in the technique of Patent Document 2, a cycle corresponding to the above-described problem is achieved with one absorption refrigerator. However, in the technique of Patent Document 2, the total amount of the solution discharged from the absorber on the single effect cycle side flows into the high-pressure regenerator composed of a falling film heat exchanger, and the total amount of the solution discharged from the high-pressure regenerator is It is a series flow that flows into a low-pressure regenerator consisting of a falling film type heat exchanger. Also, there are seven main components: an evaporator, an absorber, a low pressure regenerator, an auxiliary absorber, an auxiliary regenerator, a high pressure regenerator, and a condenser, three from the single effect cycle, and the auxiliary cycle of Patent Document 1. The number of components through which one solution circulates is increasing. For this reason, the cost increase by the increase in the amount of required holding | maintenance solutions can be considered.

An object of the present invention is to obtain an absorption refrigerator that can reduce the amount of solution retained in a configuration in which an auxiliary cycle is combined with a single effect cycle.

In order to achieve the above object, an absorption refrigerator according to an embodiment of the present invention includes an evaporator, an absorber, a low-pressure regenerator, a high-pressure regenerator, an auxiliary absorber, an auxiliary regenerator, and a condenser. And a solution pump. The evaporator, the absorber, the low pressure regenerator, the high pressure regenerator, the auxiliary absorber, and the auxiliary regenerator are a falling liquid film type. It is constituted by a heat exchanger, and the vaporizer communicates with the evaporator and the absorber, and the low-pressure regenerator and the auxiliary absorber communicate with the gas-phase portion, and the high-pressure regenerator and the auxiliary The regenerator and the condenser communicate with each other in a gas phase portion, and a solution pipe for flowing a solution from the high pressure regenerator to the absorber is connected to a solution pipe for flowing a solution from the low pressure regenerator. The solution pump is provided in the solution pipe from the merge portion to the absorber, Bottom of the serial high-pressure regenerator is located higher than the bottom surface of the low-pressure regenerator.

According to the present invention, it is possible to provide an absorption chiller capable of reducing the amount of solution retained in a configuration in which an auxiliary cycle is combined with a two single effect cycle.

The cycle system diagram of the absorption refrigerating machine concerning the embodiment of the present invention is shown. The dueling diagram of the absorption refrigerating machine concerning the embodiment of the present invention is shown.

Hereinafter, specific embodiments of the present invention will be described with reference to the drawings. Note that, in each drawing, the portions denoted by the same reference numerals indicate the same or corresponding portions.

An absorption refrigerator 100 according to an embodiment of the present invention will be described with reference to FIGS.

FIG. 1 shows a cycle system diagram of the absorption refrigerator 100 of the present embodiment.

FIG. 2 shows a dueling diagram of the absorption refrigerator 100 of the present embodiment. In FIG. 2, the horizontal axis indicates the solution temperature and the vertical axis indicates the pressure, and the state of the cycle of the present invention is shown in the During diagram composed of the isoconcentration lines of the solution.

In addition, E, A, LG, HG, AA, AG, and C in FIG. 1 and E, A, LG, HG, AA, AG, and C in FIG.

First, the overall configuration of the absorption refrigerator 100 according to the embodiment of the present invention will be described.

The absorption refrigerator 100 includes a single effect cycle side and an auxiliary cycle (two-stage absorption cycle) side, and the solution circulates independently in each cycle. The single effect cycle side includes an evaporator 1 (E), an absorber 9 (A), a low pressure regenerator 22 (LG), a high pressure regenerator 33 (HG), a condenser 40 (C), a low temperature solution heat exchanger 55, The heat exchanger element of the high temperature solution heat exchanger 56, the refrigerant pump 6, the

solution pumps

14 and 30, and the like are provided. The auxiliary cycle side includes an auxiliary absorber 16 (AA), an auxiliary regenerator 44 (AG), a heat exchanger element of an intermediate temperature solution heat exchanger 57,

solution pumps

29 and 54, and the like.

Next, the operation on the single effect cycle side will be described.

In the evaporator 1, the refrigerant stored in the lower part of the evaporator 1 by the refrigerant pump 6 is guided to the spraying device 2 through the refrigerant pipe 7 and sprayed outside the heat transfer tube of the heat exchanger 3. The dispersed refrigerant is heated by the cold water flowing in the heat transfer pipe of the heat exchanger 3 to be partially refrigerant vapor, and is led to the absorber 9 through the eliminator 8. At this time, the cold water flowing in the heat transfer tube of the heat exchanger 3 is cooled using the latent heat of vaporization 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 by the low pressure regenerator 22 and the high pressure regenerator 33 is scattered from the spray device 10 to the outside of the heat transfer tube of the heat exchanger 11. The dispersed solution absorbs the refrigerant vapor from the evaporator 1 and decreases in concentration, and then branches at the branch point A after passing through the low-temperature solution heat exchanger 55 by the solution pump 14 installed in the middle of the solution pipe 15. One is led to the low pressure regenerator 22 through the flow rate adjustment valve 32 of the solution pipe 31. The other solution branched at the branch point A is led to the high pressure regenerator 33 through the high temperature solution heat exchanger 56. Cooling water is passed through the heat transfer tube of the heat exchanger 11 of the absorber 9 in order to remove the absorption heat 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 having a reduced concentration in the absorber 9 is sprayed from the spray device 23 to the outside of the heat transfer tube of the heat exchanger 24. The dispersed solution is heated by a heat source medium flowing in the heat transfer tube 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 merge point (merging portion) B through the solution pipe 27. The refrigerant vapor separated from the concentrated solution is guided to the auxiliary absorber 16 on the auxiliary cycle side via 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 solution whose concentration is reduced by the absorber 9 and heated by the low-temperature solution heat exchanger 55 and the high-temperature solution heat exchanger 56 is sprayed from the spraying device 34 to the outside of the heat transfer tube of the heat exchanger 35. The sprayed solution is heated by a heat source medium flowing in the heat transfer tube of the heat exchanger 35 and separated into a concentrated solution and refrigerant vapor. The concentrated solution is guided to the junction 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 that have joined at the junction B is boosted by the solution pump 30 and led to the absorber 9 through the low temperature solution heat exchanger 55. The refrigerant vapor separated from the solution concentrated by the high pressure regenerator 33 is guided to the condenser 40 through the baffle 39. Heat

source medium pipes

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 tube of the heat exchanger 41 to be 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 sprayed from the spraying device 17 to the outside of the heat transfer tube of the heat exchanger 18. The sprayed solution absorbs the refrigerant vapor from the low-pressure regenerator 22 of the single effect side cycle and becomes low in concentration, and then passes through the intermediate-temperature solution heat exchanger 57 with the solution pump 29 installed in the middle of the solution pipe 28 and then the high-pressure. Guided to the regenerator 33. Cooling water is passed through the heat transfer tube of the heat exchanger 18 of the auxiliary absorber 16 in order to remove 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 has been reduced by the auxiliary absorber 16 is sprayed from the spraying device 45 to the outside of the heat transfer tube of the heat exchanger 46. The sprayed solution is heated by a heat source medium flowing in the heat transfer tube 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 intermediate temperature solution heat exchanger 57 by the solution pump 54 installed in the middle of the solution pipe 51. The refrigerant vapor separated from the concentrated solution is led to the condenser 40 through the baffle 52. Heat source

medium pipes

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 this order, for example. At this time, as shown in FIG. 2, the heat source medium is utilized 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.). be able to.

Further, in the evaporator 1, the refrigerant flows down from the spraying device above each heat exchanger in the absorber 9, the low pressure regenerator 22, the high pressure regenerator 33, the auxiliary absorber 16, and the auxiliary regenerator 44. It is a liquid film heat exchanger.

As described above, the configuration of the present embodiment communicates the gas phase portion of the low-pressure regenerator 22 on the single effect cycle side and the auxiliary absorber 16 on the auxiliary absorption cycle side, and the high-pressure regenerator 33 and the condensation on the single-effect cycle side. By connecting the gas phase section of the auxiliary regenerator 44 on the auxiliary absorption cycle side with the vessel 40, the single effect cycle and the auxiliary absorption cycle can be operated in combination. In this embodiment, an aqueous lithium bromide solution is used as the solution (absorbent), and water is used as the refrigerant.

Further, in the present embodiment, as shown in FIG. 1, the bottom surface 101 of the high pressure regenerator 33 is disposed higher than the bottom surface 102 of the low pressure regenerator 22 by a height H. The height H is set so that the liquid level of the solution flowing out from the high pressure regenerator 33 during operation is formed in the pipe 49. This eliminates the need to store the solution in the high-pressure regenerator 33 during operation, thereby reducing the amount of refrigerant together with the amount of solution.

Next, how to determine the height H will be described. During operation, for example, the liquid level of the low-pressure regenerator 22 is detected by a liquid level sensor (not shown) installed in the low-pressure regenerator 22, and if the liquid level drops, the spray amount is increased. When the surface rises, the flow rate adjustment valve 32 controls the spray amount to decrease, and the liquid level of the solution stored in the low pressure regenerator 22 is adjusted to a certain range. At this time, the liquid level height of the solution flowing out from the high pressure regenerator 33 is the pressure difference ΔP1 generated between the high pressure regenerator 33 and the low pressure regenerator 22, and the high pressure regenerator 33 including the inside of the high temperature solution heat exchanger 56. Is determined by the pressure loss ΔP2 of the pipe 49 from the junction point B to the junction point B. The liquid level height of the solution flowing out from the high pressure regenerator 33 can be reduced by the pressure difference ΔP1 with respect to the liquid level height in the low pressure regenerator 22, but is increased by the pressure loss ΔP2. If the liquid surface height of the solution stored in the low pressure regenerator 22 is 200 mm, the pressure difference ΔP1 is 200 mm, and the pressure loss ΔP2 is 1000 mm, the solution may be prevented from being stored in the high pressure regenerator 33. The possible height H is H> 1000 mm.

Here, the liquid level of the solution in the low-pressure regenerator 22, the pressure difference ΔP1 between the high-pressure regenerator 33 and the low-pressure regenerator 22, and the high-pressure regenerator 33 including the inside of the high-temperature solution heat exchanger 56 to the junction B The pressure loss ΔP2 of the pipe 49 can be easily obtained if the specifications and operating conditions of the pipe 49 and the high-temperature solution heat exchanger 56 are determined, and the high pressure regenerator from the bottom surface 102 of the low pressure regenerator 22 based on the result. The height H to the bottom surface 101 of 33 can be set and the device arrangement can be determined.

Next, functions and effects of this embodiment will be described.

The absorption refrigerator 100 of the present embodiment distributes the solution of the absorber 9 to the low pressure regenerator 22 and the high pressure regenerator 33 at the branch point A, and the solution from the low pressure regenerator 22 and the high pressure regenerator 33 is combined with the junction. The solution is combined at B and is introduced into the absorber 9 by the solution pump 30. For this reason, unlike the other elements (other pumps), the solution from the two elements, the low pressure regenerator 22 and the high pressure regenerator 33, flows into the solution pump 30.

As shown in FIG. 1, the other elements are that the absorber 5 flows into the solution pump 14, the auxiliary absorber 16 enters the solution pump 19, and the solution from the auxiliary regenerator 44 flows into the solution pump 54. , 62, 63, 64 are provided in a one-to-one relationship, and the tank is operated with a certain amount of solution stored in the tank. This is to allow a change in the amount of the solution due to the change in the concentration of the solution in the operating range and to prevent the liquid level in each solution tank from fluctuating sensitively. The pressure can be secured, and each solution pump can be driven stably.

On the other hand, the solution from the high pressure regenerator 33 and the low pressure regenerator 22 flows into the solution pump 30, but in order to drive the solution pump 30 stably, the solution tank is the same as other elements. Since one is sufficient, the low pressure regenerator 22 is provided with a solution tank 63. In the low pressure regenerator 22, the pressure loss of the solution up to the solution pump 30 is smaller than that of the high pressure regenerator 33 via the high temperature solution heat exchanger 56, so that the solution tank 63 is provided in the low pressure regenerator 22. There is an effect that the liquid level required for the stable operation of the pump 30 can be kept low.

From the above, the bottom surface 101 of the high pressure regenerator 33 is arranged at a position higher than the bottom surface 102 of the low pressure regenerator 22 so that the liquid level of the solution flowing out from the high pressure regenerator 33 during operation is formed in the pipe 49. The bottom of the high-pressure regenerator 33 was arranged so that no solution was collected during operation. This eliminates the need for a solution tank in the high-pressure regenerator 33 and reduces the amount of solution and the amount of refrigerant, thereby contributing to downsizing and cost reduction of the absorption refrigeration machine 100. Further, since the heat capacity of the retained liquid amount can be reduced by reducing the amount of solution and the amount of refrigerant, the start-up characteristics of the absorption chiller 100 can be improved.

In addition, this invention is not limited to the Example mentioned above. A person skilled in the art can make various additions and changes within the scope of the present invention.

1: Evaporator 9: Absorber 30: Solution pump 27, 49: Solution pipe 16: Auxiliary absorber 22: Low pressure regenerator 33: High pressure regenerator 40: Condenser 44: Auxiliary regenerator 56: High temperature solution heat exchanger 41 : Condenser 101: Bottom surface of high pressure regenerator 102: Bottom surface of low pressure regenerator

Claims

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, the absorber, the low-pressure regenerator, the high-pressure regenerator, the auxiliary absorber, and the auxiliary regenerator are configured by a falling film type heat exchanger,
The vaporizer and the absorber communicate with each other in a gas phase part,
The low-pressure regenerator and the auxiliary absorber communicate with the gas phase part,
The high-pressure regenerator, the auxiliary regenerator, and the condenser are in communication with a gas phase part,
The solution pipe for flowing the solution from the high-pressure regenerator to the absorber has a merging portion connected to the solution pipe for flowing the solution from the low-pressure regenerator,
The solution pump is provided in the solution pipe from the junction to the absorber,
The absorption refrigerating machine, wherein a bottom surface of the high pressure regenerator is disposed at a position higher than a bottom surface of the low pressure regenerator.
The position of the bottom surface of the high pressure regenerator with respect to the bottom surface of the low pressure regenerator is the level of the solution flowing out of the high pressure regenerator in the solution pipe for flowing the solution from the high pressure regenerator to the absorber. The absorption refrigerator according to claim 1, wherein the absorption refrigerator is set so as to be formed.
The position of the bottom surface of the high pressure regenerator with respect to the bottom surface of the low pressure regenerator is the pressure difference between the high pressure regenerator and the low pressure regenerator, and the pressure loss of the solution pipe from the high pressure regenerator to the junction. The absorption refrigerator according to claim 2, wherein the absorption refrigerator is set based on the liquid level of the solution in the low-pressure regenerator.
High-temperature solution heat exchange in which heat is exchanged between the solution in the solution pipe for flowing the solution from the high-pressure regenerator to the junction and the solution in the solution pipe through which the solution flows from the absorber to the high-pressure regenerator. The absorption refrigerator according to any one of claims 1 to 3, further comprising a refrigerator.