JP6632951B2 - Absorption refrigerator - Google Patents

Description

  The present invention relates to an absorption refrigerator.

  Since the absorption refrigerator can be driven by heat, it can supply cold heat using hot water discharged as exhaust heat as a drive 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 Literature 1 describes that a regenerator can be an absorption refrigerator having two two-stage absorption cycles and can supply cold heat using hot water having a lower temperature than that of the absorption refrigerator having a single-effect cycle as a driving heat source. .

  Patent Literature 2 discloses an absorption refrigerator in which a single-effect cycle and an auxiliary cycle (two-stage absorption cycle) are combined. 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 an absorber, a high-pressure regenerator, a low-pressure regenerator, and an absorber. The auxiliary cycle side is composed of an auxiliary absorber and an auxiliary regenerator. The gas phase of the auxiliary absorber communicates with the low pressure regenerator, and the gas phase of the auxiliary regenerator is the gas phase of the high pressure regenerator and condenser. Is described. Patent Literature 2 states that one absorption refrigerator can use hot water of a driving heat source from a temperature required for an absorption refrigerator in a single-effect cycle to a temperature required for an absorption refrigerator in a two-stage absorption cycle.

JP 2004-211979 (FIG. 6) Korean Patent Application Publication No. 10-10074641 (FIG. 2)

  In order to save energy, it is effective means to generate and reuse a larger amount of cold heat from one exhaust heat source. As means for that purpose, for example, hot water of about 90 ° C. is used as a driving heat source of an absorption refrigerator of a single-effect cycle, and thereafter, the cooled water 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-type refrigerators each having a different cycle configuration are required, and the cooling water and the cooling water piping system are two, which complicates the piping configuration, increases the installation area, and increases the cost. Become. Furthermore, with two absorption chillers, the number of solution pumps and refrigerant pumps is almost doubled, which increases the power consumption and doubles the solution amount and the refrigerant amount.

  On the other hand, in the technique of Patent Document 2, a cycle corresponding to the above problem is achieved with one absorption refrigerator. However, in the technique of Patent Document 2, the entire amount of the solution flowing out of the absorber on the single-effect cycle side flows into a high-pressure regenerator composed of a falling film heat exchanger, and the entire amount of the solution exiting the high-pressure regenerator is reduced. It is a series flow that flows into a low-pressure regenerator consisting of a falling liquid film type heat exchanger. In addition, the main components are an evaporator, an absorber, a low-pressure regenerator, an auxiliary absorber, an auxiliary regenerator, a high-pressure regenerator, and a condenser, three from a single-effect cycle, and an auxiliary cycle of Patent Document 1. More components circulate through one solution. For this reason, the cost may be increased due to an increase in the required amount of the retained solution.

  An object of the present invention is to provide an absorption refrigerator capable of reducing the solution holding amount in a configuration in which an auxiliary cycle is combined with a single-effect cycle.

  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, Vessel, a solution pump, the evaporator, the absorber, the low-pressure regenerator, the high-pressure regenerator, the auxiliary absorber, and the auxiliary regenerator, the falling liquid film type The evaporator and the absorber are constituted by a heat exchanger, the gas phase communicates with the evaporator and the absorber, the gas phase communicates with the low-pressure regenerator and the auxiliary absorber, and the high-pressure regenerator and the auxiliary The regenerator and the condenser communicate with each other in a gas phase, 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. Wherein the solution pump is provided in the solution pipe from the junction to the absorber, and The bottom surface of the high-pressure regenerator is located higher than the bottom surface of the low-pressure regenerator.

  ADVANTAGE OF THE INVENTION According to this invention, in the structure which combined the auxiliary | assistant cycle with 2 single effect cycles, the absorption type refrigerator which can reduce the solution holding quantity can be provided.

1 shows a cycle system diagram of an absorption refrigerator according to an embodiment of the present invention. 1 shows a During diagram of an absorption refrigerator according to an embodiment of the present invention.

  Hereinafter, specific examples of the present invention will be described with reference to the drawings. In each of the drawings, 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 an absorption refrigerator 100 of the present embodiment.

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

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

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

  The absorption refrigerator 100 has a single-effect cycle side and an auxiliary cycle (two-stage absorption cycle) side, and the solution circulates independently in each cycle. On the single-effect cycle side, evaporator 1 (E), absorber 9 (A), low-pressure regenerator 22 (LG), high-pressure regenerator 33 (HG), condenser 40 (C), 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, 30, and the like are provided. The auxiliary cycle side includes the auxiliary absorber 16 (AA), the auxiliary regenerator 44 (AG), heat exchanger elements of the medium temperature solution heat exchanger 57, and the solution pumps 29 and 54.

  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 dispersing device 2 through the refrigerant pipe 7 and is dispersed outside the heat transfer tube of the heat exchanger 3. The sprayed refrigerant is heated by cold water flowing in the heat transfer tube of the heat exchanger 3 and partially becomes refrigerant vapor, and is guided to the absorber 9 via the eliminator 8. At this time, the chilled water flowing in the heat transfer tube 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, and cold water for supplying cold to the load side flows through the heat exchanger 3.

  In the absorber 9, the solution concentrated in the low-pressure regenerator 22 and the high-pressure regenerator 33 is dispersed from the spraying device 10 to the outside of the heat transfer tube of the heat exchanger 11. After the sprayed solution absorbs the refrigerant vapor from the evaporator 1 and its concentration is reduced, it is branched 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 guided to the low-pressure regenerator 22 via the flow control 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 whose concentration has been reduced by the absorber 9 is sprayed from the spraying device 23 to the outside of the heat transfer tube of the heat exchanger 24. The sprayed solution is heated by a heat source medium flowing in the heat transfer tube of the heat exchanger 24, and is separated into a concentrated solution and a refrigerant vapor. The concentrated solution merges with the solution from the high-pressure regenerator 33 at the junction (junction) B through the solution pipe 27. The refrigerant vapor separated from the concentrated solution is led 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 has been reduced in the absorber 9 and has been heated in 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 is separated into a concentrated solution and a refrigerant vapor. The concentrated solution is led to the junction B through a high-temperature solution heat exchanger 56 installed in the middle of the solution pipe 49. The concentrated solutions from the low-pressure regenerator 22 and the high-pressure regenerator 33 that have joined at the junction B are boosted in pressure 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 solution concentrated in the high-pressure regenerator 33 is guided to the condenser 40 via 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 by 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 in the single-effect side cycle, and the concentration thereof is reduced. After passing through the medium-temperature solution heat exchanger 57 by the solution pump 29 installed in the middle of the solution pipe 28, the high-pressure It is led to the regenerator 33. Cooling water is passed through the heat exchanger tubes of the heat exchanger 18 of the auxiliary absorber 16 in order to remove the heat of absorption 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 is separated into a concentrated solution and a refrigerant vapor. The concentrated solution is guided to the auxiliary absorber 16 through the medium-temperature solution heat exchanger 57 by the solution pump 54 provided in the middle of the solution pipe 51. The refrigerant vapor separated from the concentrated solution is led to the condenser 40 via 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 flows 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, for example. At this time, as shown in FIG. 2, the heat source medium is used 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 auxiliary regenerator 44 outlet (about 60 ° C.). be able to.

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

  As described above, in the configuration of the present embodiment, the low-pressure regenerator 22 on the single-effect cycle side communicates with the gas phase of the auxiliary absorber 16 on the auxiliary absorption cycle side, and the high-pressure regenerator 33 on the single-effect cycle side and the condenser By communicating the reactor 40 with the gas phase of the auxiliary regenerator 44 on the auxiliary absorption cycle side, it is possible to operate the single effect cycle and the auxiliary absorption cycle in combination. In this embodiment, an aqueous solution of lithium bromide is used as a solution (absorbent), and water is used as a refrigerant.

  In this embodiment, as shown in FIG. 1, the bottom 101 of the high-pressure regenerator 33 is arranged higher than the bottom 102 of the low-pressure regenerator 22 by the height H. The height H is set so that the level of the solution flowing out of 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, and can reduce the amount of the refrigerant together with the amount of the 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 when the liquid level falls, the spraying amount is increased. When the surface rises, the spraying amount is controlled by the flow control valve 32 so as to be reduced, and the liquid level of the solution stored in the low-pressure regenerator 22 is adjusted within a certain range. At this time, the liquid level of the solution flowing out of the high-pressure regenerator 33 depends on 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 to the junction B. The liquid level of the solution flowing out of the high-pressure regenerator 33 can be made lower than the liquid level in the low-pressure regenerator 22 by the pressure difference ΔP1, but higher by the pressure loss ΔP2. Assuming that the liquid level 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, it is necessary to prevent the solution from being stored in the high-pressure regenerator 33. The resulting 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 junction B from the high-pressure regenerator 33 including the inside of the high-temperature solution heat exchanger 56 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. By setting the height H to the bottom surface 101 of the device 33, the device arrangement can be determined.

  Next, the operation and effect of the present embodiment will be described.

  The absorption refrigerator 100 of the present embodiment distributes the solution in the absorber 9 to the low-pressure regenerator 22 and the high-pressure regenerator 33 at the branch point A, and combines the solutions from the low-pressure regenerator 22 and the high-pressure regenerator 33 at a junction. The solution is merged at B and flows into the absorber 9 by the solution pump 30. Therefore, unlike the other components (other pumps), the solution pump 30 receives the solution from the low-pressure regenerator 22 and the high-pressure regenerator 33 and the two components.

  As shown in FIG. 1, the solution pump 14 receives the solution from the absorber 5, the solution pump 19 receives the solution from the auxiliary absorber 16, the solution pump 54 receives the solution from the auxiliary regenerator 44, and the solution tank 61. , 62, 63, and 64 are provided in a one-to-one correspondence, and the tank is operated with a certain amount of solution stored therein. This is to allow a change in the solution volume 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 must be Since one is sufficient, the solution tank 63 is provided in the low-pressure regenerator 22. 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. There is an effect that the liquid level required for the pump 30 to operate stably 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 of the high-pressure regenerator 33 during operation is formed in the pipe 49. At the bottom of the high-pressure regenerator 33, a device was arranged so that the solution did not accumulate during operation. This eliminates the need for a solution tank in the high-pressure regenerator 33, and can reduce the amount of solution and the amount of refrigerant, thereby contributing to downsizing and cost reduction of the absorption refrigerator 100. In addition, since the heat capacity of the retained liquid amount can be reduced by reducing the amount of the solution and the amount of the refrigerant, the start-up characteristics of the absorption refrigerator 100 can be improved.

  Note that the present invention is not limited to the above-described embodiment. A person skilled in the art can make various additions and changes without departing from 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 of high pressure regenerator 102 ： Bottom of low pressure regenerator

Claims (4)

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, configured by a falling liquid film type heat exchanger,
The evaporator and the absorber communicate with a gas phase,
The low-pressure regenerator and the auxiliary absorber communicate with a gas phase,
The high-pressure regenerator, the auxiliary regenerator, and the condenser communicate with a gas phase,
A solution pipe for flowing the solution from the high-pressure regenerator to the absorber has a junction connected to a 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,
An absorption refrigerator, wherein a bottom surface of the high-pressure regenerator is arranged 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 in a solution pipe for flowing a solution from the high-pressure regenerator to the absorber, and a liquid level of a solution flowing out of the high-pressure regenerator. The absorption chiller according to claim 1, wherein the absorption chiller 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 a pressure difference between the high-pressure regenerator and the low-pressure regenerator, and a 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: and a liquid level of the solution in the low-pressure regenerator.   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 for the solution flowing from the absorber to the high-pressure regenerator perform high-temperature solution heat exchange in which heat exchange is performed. The absorption refrigerator according to any one of claims 1 to 3, further comprising a vessel.

Images