JP6779760B2 - Absorption chiller - Google Patents

Description

The present invention relates to an absorption chiller.

Conventionally, an absorption chiller that obtains a cold liquid by a circulation cycle of a regenerator, a condenser, an evaporator, and an absorber has been proposed (see, for example, Patent Document 1). However, in the absorption chiller described in Patent Document 1, in the evaporator, for various reasons such as the wettability of the heat transfer tube through which the cold liquid flows in the evaporator and the dripping variation of the refrigerant dripper that drops the refrigerant liquid. The amount of unevaporated refrigerant liquid that does not evaporate may increase. Since such an unevaporated refrigerant liquid becomes an ineffective refrigerant that does not contribute to the so-called refrigerating capacity, the refrigerating capacity decreases when the unevaporated refrigerant liquid increases.

Therefore, in order to prevent a decrease in refrigerating capacity, an absorption chiller provided with a refrigerant reservoir for storing the unevaporated refrigerant liquid has been proposed (see, for example, Patent Document 2). Since such an absorption chiller is provided with a path for sending the unevaporated refrigerant liquid in the refrigerant reservoir to the evaporator, the unevaporated refrigerant liquid can be supplied to the evaporator again to evaporate. In particular, since the absorption chiller described in Patent Document 2 includes a pump for feeding the refrigerant liquid from the refrigerant reservoir to the evaporator, the total amount of refrigerant can be increased as compared with the absorption chiller described in Patent Document 1. As a result, the amount of refrigerant dropped onto the evaporator can be increased, and as a result, stable refrigerating capacity can be expected without being affected by the wettability of the heat transfer tube.

Further, an absorption chiller in which a heat exchanger is installed in the middle of a pipe for sending the refrigerant liquid condensed by the condenser to the evaporator has also been proposed (see, for example, Patent Documents 3 and 4). In such an absorption chiller, cold water used for air conditioning equipment or the like is introduced into the heat exchanger (see Patent Document 3), or cooling water flowing through a cooling water circuit is introduced (see Patent Document 4). By exchanging heat with, the temperature of the refrigerant liquid is lowered and flows into the evaporator. As a result, the amount of flash steam is reduced, the amount of refrigerant liquid adhering around the heat transfer tube of the evaporator due to the scattering of steam is reduced, the effective heat transfer area of the evaporator is increased, and the effective refrigerant can be increased. That is, the refrigerating capacity can be improved.

Japanese Unexamined Patent Publication No. 3-211371 Japanese Unexamined Patent Publication No. 1-116262 JP-A-2002-181400 JP-A-2002-310525

However, since the absorption chiller described in Patent Document 2 requires a pump, the cost of the pump itself and the running cost due to the pump power are extra, and the pump may not operate, so that the reliability is high. It also leads to a decline.

Further, the absorption chiller described in Patent Document 3 aims to improve the refrigerating capacity by reducing the flash steam and increasing the effective refrigerant, but for cooling the refrigerant liquid from the condenser to the evaporator, Since the cold water used for the air conditioner or the like is used, the cooling efficiency of the air conditioner or the like is lowered, and it cannot be said that it contributes to the improvement of the refrigerating capacity as a whole.

Further, the absorption chiller described in Patent Document 4 is also intended to increase the refrigerating capacity by reducing the flash vapor and increasing the effective refrigerant, but the cooling water (for example, 32 ° C.) and the refrigerant liquid (for example, 32 ° C.) and the refrigerant liquid (for example) Since the temperature difference from 40 ° C.) is small and the temperature of the refrigerant liquid drops only slightly, as a result, it does not contribute much to the improvement of the refrigerating capacity.

The present invention has been made to solve such a conventional problem, and an object of the present invention is to improve refrigerating capacity while preventing cost increase and reliability decrease due to a pump. The purpose is to provide an absorption chiller.

The absorption type refrigerator of the present invention is condensed by a regenerator that heats a rare solution to generate a refrigerant vapor and a concentrated solution, a condenser that condenses the refrigerant vapor generated by the regenerator, and the condenser. An evaporator having a refrigerant distributor that accepts the refrigerant liquid and drops it on a heat transfer tube through which the cold liquid flows to evaporate it, and the refrigerant vapor evaporated by the evaporator is absorbed by the concentrated solution generated by the regenerator. An absorption refrigerating machine comprising an absorber for producing a rare solution and forming an absorption refrigeration cycle for sending the rare solution produced by the absorber to the regenerator, wherein the condenser and the evaporator are used. The refrigerant liquid in the refrigerant liquid pipe uses the refrigerant liquid pipe that transfers the refrigerant liquid from the condenser to the evaporator by utilizing the height difference and the unevaporated refrigerant liquid that has not been evaporated by dropping into the heat transfer pipe. The refrigerant reservoir, which is provided at the bottom of the heat transfer tube and stores the unevaporated refrigerant liquid that has not been dropped and evaporated in the heat transfer tube, and the inlet and outlet are both connected to the refrigerant liquid pipe. A refrigerant cooler having a heat exchange pipe that is immersed in the unevaporated refrigerant liquid stored in the refrigerant reservoir as the refrigerant liquid flows, and one end connected to the refrigerant reservoir and the other end. Is formed by a substantially U-shaped or substantially V-shaped pipe that has an open end and is convex downward, and is heated by the rare solution generated by the absorber when the refrigerator is stopped to boil the unevaporated refrigerant liquid in the pipe. It is characterized by including a bubble pump that transfers the unevaporated refrigerant liquid stored in the refrigerant reservoir from one end side to the other end side and discharges it from the open end of the other end .

According to the absorption type refrigerator of the present invention, the refrigerant in the refrigerant liquid pipe uses the refrigerant liquid pipe that transfers the refrigerant liquid from the condenser to the evaporator and the unevaporated refrigerant liquid that has not been evaporated by dropping into the heat transfer pipe. In order to provide a refrigerant cooler that exchanges heat with the liquid, the stage where the refrigerant liquid is cooled by the refrigerant cooler in the process of being transferred from the condenser to the evaporator by the refrigerant liquid pipe and accepted by the refrigerant distributor of the evaporator. Then, the amount of flash evaporation can be suppressed. As a result, the amount of the refrigerant liquid dropped on the heat transfer tube can be increased, and the effective area of the heat transfer tube can be expected to increase due to the decrease in the flash vapor, so that the refrigerating capacity can be improved. Further, since the refrigerant liquid is transferred from the condenser to the evaporator by utilizing the height difference between the condenser and the evaporator, it is not necessary to install a pump. Therefore, it is possible to improve the refrigerating capacity while preventing the cost increase and the reliability decrease due to the pump.

Further , a state in which a refrigerant reservoir for storing the unevaporated refrigerant liquid that has been dropped on the heat transfer tube and has not evaporated and a state in which the refrigerant liquid is connected to the refrigerant liquid pipe and flows and is immersed in the unevaporated refrigerant liquid stored in the refrigerant reservoir. In order to provide a heat exchange pipe, a refrigerant reservoir such as a container for storing unevaporated refrigerant liquid is installed at the bottom of the heat transfer pipe, and a heat exchange pipe through which the refrigerant liquid flows is provided in the refrigerant reservoir to cool the refrigerant. A device can be configured, and a refrigerant cooler can be realized with a relatively simple configuration.

Further , since the bubble pump that discharges the unevaporated refrigerant liquid stored in the refrigerant reservoir by boiling the unevaporated refrigerant liquid in the pipe that is heated when the refrigerator is stopped is further provided, the unevaporated refrigerant liquid stored in the refrigerant reservoir is further provided. It is possible to prevent damage to the heat exchange pipe and the refrigerant liquid pipe due to the freezing of the refrigerant liquid.

Further, the absorption chiller of the present invention further includes a solution pump that sends the rare solution produced by the absorber to the regenerator during the operation of the refrigerator and stops the operation when the refrigerator is stopped. It is preferable that the solution pump is not immersed in the rare solution during operation, but is partially immersed in the rare solution when the solution pump is stopped to be heated.

According to this absorption chiller, a solution pump that sends a rare solution generated by the absorber during the operation of the refrigerator to the regenerator and stops the operation when the refrigerator is stopped is further provided. Here, when the solution pump is stopped, the rare solution is not sent to the regenerator and the liquid level of the rare solution rises. This makes it possible to construct a bubble pump that is heated by not immersing it in the rare solution when the solution pump is operating and by immersing a part of it in the rare solution when the solution pump is stopped, without the need for a heating heater or the like. The bubble pump can be operated to discharge the unevaporated refrigerant solution stored in the refrigerant reservoir.

Further, in the absorption chiller of the present invention, the bubble pump has a straight pipe that hangs substantially linearly from one end side and a straight pipe that extends from the straight pipe and extends in the vertical direction so that the other end side is higher than one end side. On the other hand, it is preferable that the discharge pipe is provided with a discharge pipe having an inclined portion, and at least a part of the inclined portion of the discharge pipe is immersed in a rare solution when the solution pump is stopped.

According to this absorption chiller, the bubble pump includes a straight pipe and a discharge pipe having an inclined portion so that the other end side is higher than one end side, and the discharge pipe is when the solution pump is stopped. A part of the inclined part is immersed in a rare solution. Therefore, the unevaporated refrigerant liquid in the inclined portion moves to the other end so as to be guided along the inclined portion and is discharged from the open end. Then, once the unevaporated refrigerant liquid is discharged, the unevaporated refrigerant liquid in the refrigerant reservoir reaches the discharge pipe through the straight pipe along the flow, and is discharged from the open end at the other end through the discharge pipe. Therefore, the unevaporated refrigerant liquid can be efficiently discharged.

Further, in the absorption chiller of the present invention, it is preferable that the straight pipe has a larger diameter than the discharge pipe.

According to this absorption chiller, since the straight pipe has a larger pipe diameter than the discharge pipe, the volume of the straight pipe increases and convection of the unevaporated refrigerant liquid occurs in the straight pipe. The unevaporated refrigerant liquid can be preferentially heated and boiled, and the unevaporated refrigerant liquid can be discharged more efficiently.

Further, in the absorption chiller of the present invention, the straight pipe includes a first straight pipe that hangs down substantially linearly from the refrigerant reservoir and a second straight that covers at least a part of the outer peripheral side of the first straight pipe. It has a double structure including a pipe, and it is preferable that the discharge pipe is connected to a position of the second straight pipe above the lower end of the first straight pipe.

According to this absorption chiller, the straight pipe has a double structure consisting of a first straight pipe and a second straight pipe that covers at least a part of the outer peripheral side of the first straight pipe. The unevaporated refrigerant liquid in the straight pipe is difficult to heat, and not only the unevaporated refrigerant liquid in the discharge pipe but also the unevaporated refrigerant liquid in the second straight pipe can be preferentially heated and boiled. Since the discharge pipe is connected to a position above the lower end of the first straight pipe in the second straight pipe, the unevaporated refrigerant liquid (refrigerant vapor) heated and boiled in the second straight pipe. Can be easily guided into the discharge pipe. Therefore, the unevaporated refrigerant liquid can be discharged more efficiently.

Needless to say, the concept of an absorption chiller includes an absorption chiller-heater capable of heating operation in addition to the functions of the absorption chiller.

According to the present invention, it is possible to provide an absorption chiller capable of improving the refrigerating capacity while preventing an increase in cost and a decrease in reliability due to a pump.

It is a schematic block diagram which shows the absorption chiller which concerns on 1st Embodiment of this invention. It is a perspective view which shows the detail of the refrigerant cooler shown in FIG. It is the schematic for demonstrating the operation of the absorption chiller which concerns on 1st comparative example. It is the schematic for demonstrating the operation of the absorption chiller which concerns on 2nd comparative example. It is the schematic for demonstrating the operation of the absorption chiller which concerns on 1st Embodiment. It is a schematic block diagram which shows the absorption chiller which concerns on 2nd Embodiment. It is sectional drawing which shows the detail of the bubble pump shown in FIG. It is sectional drawing which shows the 1st modification of the bubble pump shown in FIG. It is sectional drawing which shows the 2nd modification of the bubble pump shown in FIG. It is a schematic block diagram which shows the absorption chiller which concerns on 3rd Embodiment.

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. The present invention is not limited to the embodiments shown below, and can be appropriately modified without departing from the spirit of the present invention. Further, in the embodiments shown below, some parts of the configuration are omitted from the illustration and description, but the details of the omitted technology are within a range that does not conflict with the contents described below. Needless to say, publicly known or well-known techniques are appropriately applied.

FIG. 1 is a schematic configuration diagram showing an absorption chiller according to the first embodiment of the present invention. In the following description, the absorption chiller will be described as an example, but the present invention is not limited to this, and even if it is applied to an absorption chiller-heater capable of further heating operation if it has the function of the absorption chiller. Good.

The absorption chiller 1 shown in FIG. 1 includes a regenerator 10, a condenser 20, an evaporator 30, and an absorber 40, and cools a cold liquid by an absorption refrigeration cycle thereof. Further, the absorption chiller 1 includes a solution pump 50.

In the regenerator 10, for example, water as a refrigerant (hereinafter, what is vaporized as a refrigerant is referred to as refrigerant vapor, and what is liquefied as a refrigerant is referred to as a refrigerant liquid) and lithium bromide (LiBr) as an absorbing liquid are used. It heats a mixed rare solution (a solution with a low concentration of absorption liquid). A heat source is arranged in the regenerator 10, and the rare solution is heated by the heat source. The regenerator 10 generates refrigerant vapor and a concentrated solution (a solution having a high concentration of an absorbing solution) by releasing vapor from the rare solution by this heating.

The condenser 20 liquefies (condenses) the refrigerant vapor supplied from the regenerator 10. A first cold water heat transfer tube 21 is inserted into the condenser 20. Cooling water is supplied to the first chilled water heat transfer tube 21 from a cooling tower or the like, and the evaporated refrigerant vapor is liquefied by the cooling water in the first chilled water heat transfer tube 21. Further, the refrigerant liquid liquefied by the condenser 20 is supplied to the evaporator 30.

The evaporator 30 evaporates the refrigerant liquid. The evaporator 30 includes a refrigerant distributor 31 that receives the refrigerant liquid condensed by the condenser 20. The refrigerant distributor 31 drops (sprays) the received refrigerant liquid. Further, a second chilled water heat transfer tube 32 connected to an indoor unit or the like is provided in the evaporator 30. The second cold water heat transfer tube (heat transfer tube) 32 is connected to, for example, an indoor unit, and water warmed by cooling the indoor air by the indoor unit is flowing. Further, the inside of the evaporator 30 is in a vacuum state. Therefore, the evaporation temperature of water as a refrigerant is about 5 ° C. Therefore, the refrigerant liquid dropped on the second chilled water heat transfer tube 32 by the refrigerant distributor 31 evaporates depending on the temperature of the second chilled water heat transfer tube 32. Further, the temperature of the water in the second cold water heat transfer tube 32 is deprived by the evaporation of the refrigerant liquid. As a result, the water in the second cold water heat transfer tube 32 is supplied to the indoor unit as cold water (an example of cold liquid), and the indoor unit uses the cold water to supply cold air into the room.

The absorber 40 absorbs the refrigerant vapor evaporated in the evaporator 30. A concentrated solution is supplied from the regenerator 10 into the absorber 40, and the refrigerant vapor is absorbed by the concentrated solution to generate a rare solution. A third cold water heat transfer tube 41 is inserted through the absorber 40. Cooling water is flowing through the third cold water heat transfer tube 41, and the absorbed heat generated by the absorption of the refrigerant of the concentrated solution is removed by the cooling water of the third cold water heat transfer tube 41. The third chilled water heat transfer tube 41 is connected to the first chilled water heat transfer tube 21. Further, the absorber 40 supplies the rare solution whose concentration has decreased due to the absorption of the refrigerant to the regenerator 10 by the solution pump 50.

Further, the absorption chiller 1 according to the present embodiment includes a refrigerant liquid pipe 61, a rare solution pipe 62, a concentrated solution pipe 63, and a refrigerant cooler 70.

The refrigerant liquid pipe 61 is a pipe for transferring the refrigerant liquid from the condenser 20 to the evaporator 30. The refrigerant liquid pipe 61 transfers the refrigerant liquid from the condenser 20 to the evaporator 30 by utilizing the height difference between the condenser 20 and the evaporator 30. Therefore, the refrigerant liquid pipe 61 is not provided with a pump for generating transfer power.

The rare solution pipe 62 is a pipe for transferring the rare solution in the absorber 40 to the regenerator 10. The above-mentioned solution pump 50 is provided on the rare solution pipe 62, and the rare solution is transferred from the absorber 40 to the regenerator 10 by the solution pump 50.

The concentrated solution pipe 63 is a pipe for transferring the concentrated solution obtained by the regenerator 10 to the absorber 40. The concentrated solution pipe 63 is also configured to transfer the concentrated solution from the regenerator 10 to the absorber 40 by utilizing the height difference between the regenerator 10 and the absorber 40. The concentrated solution pipe 63 is a pipe for transferring the concentrated solution by utilizing the height difference, but the present invention is not limited to this, and a means for transferring the concentrated solution such as a pump may be provided.

The refrigerant cooler 70 exchanges heat with the refrigerant liquid in the refrigerant liquid pipe 61 by utilizing the unevaporated refrigerant liquid that has not been evaporated by dropping into the second cold water heat transfer pipe 32. FIG. 2 is a perspective view showing details of the refrigerant cooler 70 shown in FIG.

As shown in FIG. 2, the refrigerant cooler 70 is roughly composed of a refrigerant reservoir 71 and a heat exchange pipe 72. The refrigerant reservoir 71 is a tray-shaped container provided below the second chilled water heat transfer tube 32 and for storing the unevaporated refrigerant liquid that has not been dropped and evaporated on the second chilled water heat transfer tube 32. In particular, in the present embodiment, the refrigerant reservoir 71 is a container having a rectangular shape in a plan view.

The heat exchange pipe 72 is in a state in which both the inlet 73 and the outlet 74 are connected to the refrigerant liquid pipe 61 so that the refrigerant liquid flows and is immersed in the unevaporated refrigerant liquid stored in the refrigerant reservoir 71. The heat exchange pipe 72 is specifically composed of eight straight pipes 75a to 75h and five header members 76a to 76e.

The eight straight pipes 75a to 75h are arranged inside the refrigerant reservoir 71 (that is, inside the container) along the longitudinal direction of the container, and the five header members 76a to 76e are the outer surfaces of the refrigerant reservoir 71 (that is, inside the container). It is installed outside the container, especially on the outer surface of the short side of the rectangular container). Further, the eight straight pipes 75a to 75h and the five header members 76a to 76e are in a communicating state, and the refrigerant liquid can flow through each of them.

In such a refrigerant cooler 70, the inlet 73 side of the heat exchange pipe 72 is connected to the first header member 76a, and the first header member 76a is connected to the first and second straight pipes 75a and 75b. There is. Therefore, the refrigerant liquid from the refrigerant liquid pipe 61 flows through the first and second straight pipes 75a and 75b through the first header member 76a.

Further, the first and second straight pipes 75a and 75b are connected to the second header member 76b. The second header member 76b is also connected to the third and fourth straight pipes 75c and 75d. Therefore, the refrigerant liquid flowing through the first and second straight pipes 75a and 75b flows through the third and fourth straight pipes 75c and 75d through the second header member 76b.

Further, the third and fourth straight pipes 75c and 75d are connected to the third header member 76c. The third header member 76c is also connected to the fifth and sixth straight pipes 75e and 75f. In addition, the fifth and sixth straight pipes 75e and 75f are connected to the fourth header member 76d. The fourth header member 76d is also connected to the seventh and eighth straight pipes 75g and 75h. The seventh and eighth straight pipes 75g and 75h are connected to the fifth header member 76e connected to the outlet 74. Therefore, the refrigerant liquid flowing through the third and fourth straight pipes 75c and 75d reaches the fifth and sixth straight pipes 75e and 75f via the third header member 76c, and reaches the fifth and sixth straight pipes 75e and 75f. The refrigerant liquid flowing through the above reaches 75 g and 75 h of the seventh and eighth straight pipes via the fourth header member 76d. The refrigerant liquid flowing through the 7th and 8th straight pipes 75g and 75h returns to the refrigerant liquid pipe 61 (refrigerant liquid pipe 61 on the evaporator 30 side) from the outlet 74 through the fifth header member 76e.

Further, since the unevaporated refrigerant liquid is stored in the refrigerant storage portion 71 and the eight straight pipes 75a to 75h are immersed in the unevaporated refrigerant liquid, the refrigerant liquid pipe 61 on the condenser 20 side passes through the inlet 73. The refrigerant liquid that has flowed in will be heat exchanged (cooled), cooled, and then returned to the refrigerant liquid pipe 61 on the evaporator 30 side.

Next, the operation of the absorption chiller 1 according to the first embodiment will be described, but prior to this, the operation of the absorption chiller 1 according to the comparative example will be described. FIG. 3 is a schematic diagram for explaining the operation of the absorption chiller according to the first comparative example, and FIG. 4 is a schematic diagram for explaining the operation of the absorption chiller according to the second comparative example. is there. The absorption chiller 100 according to the first comparative example shown in FIG. 3 has a configuration similar to that of Patent Document 1, and the absorption chiller 200 according to the second comparative example shown in FIG. 4 has a configuration similar to that of Patent Document 2. It has a structure close to.

As shown in FIG. 3, in the absorption chiller 100 of the first comparative example, it is assumed that an amount of "107.5" of the refrigerant liquid flows from the condenser 120 into the refrigerant liquid pipe 161 at 40 ° C. In the first comparative example, since the refrigerant liquid pipe 161 does not have the refrigerant cooler 70, the amount of the refrigerant liquid of “107.5” at 40 ° C. directly reaches the refrigerant distributor 131. Therefore, a relatively large amount of flash vapor (amount of "5.5" flash vapor) is generated. In addition, the temperature of the refrigerant liquid drops due to the generation of flash steam. Therefore, at 6.5 ° C., an amount of "102" of the refrigerant liquid is dropped onto the second cold water heat transfer tube 132.

Here, in the first comparative example, the amount of the ineffective refrigerant may increase due to variations in the product such as the wettability of the second cold water heat transfer tube 132. Therefore, even if the design is initially based on the expectation that the amount of the ineffective refrigerant is about "2", in the evaporator 130, for example, the amount of the refrigerant liquid of "5" does not evaporate and becomes an ineffective refrigerant. , The amount of the refrigerant liquid of "97" may evaporate to become the refrigerant vapor. In such a case, since the capacity contribution portion is the amount of the evaporated "97", the absorption chiller 100 according to the first comparative example has a problem in terms of refrigerating capacity.

Further, as shown in FIG. 4, in the absorption chiller 200 of the second comparative example, it is assumed that an amount of "107.5" of the refrigerant liquid flows from the condenser 220 into the refrigerant liquid pipe 261 at 40 ° C. This refrigerant liquid reaches the refrigerant storage portion 271 that stores the unevaporated refrigerant liquid located at the lower part of the evaporator 230. At the stage where the amount of the refrigerant liquid of "107.5" flows into the refrigerant reservoir 271 at 40 ° C., the amount of the unevaporated refrigerant liquid of "5.5" is used for cooling, and the amount of the unevaporated refrigerant liquid of "2" is not. The evaporated refrigerant liquid scatters. Then, the unevaporated refrigerant liquid in the refrigerant reservoir 271 reaches the refrigerant distributor 231 of the evaporator 230 by the refrigerant liquid pump P. At this time, an amount of "200 to 300" of the refrigerant liquid is sent to the refrigerant distributor 231 of the evaporator 230 at 6.5 ° C. Therefore, the flash steam is not generated due to the low temperature, and a large amount of the refrigerant liquid of "200 to 300" is dropped on the second cold water heat transfer tube 232.

Here, in the second comparative example, since a large amount of refrigerant liquid is dropped on the second cold water heat transfer tube 232, it is not easily affected by the wettability of the second cold water heat transfer tube 232, and stable refrigerating capacity is expected. Can be done. That is, in the evaporator 230, the amount of the refrigerant liquid of "100" evaporates to become the refrigerant vapor (the amount of the refrigerant liquid of "100" becomes the capacity contribution portion). In addition, since a large amount of the refrigerant liquid is dropped, the amount of the refrigerant liquid of "100 to 200" becomes the unevaporated refrigerant liquid.

However, in the absorption chiller 200 according to the second comparative example, since it is necessary to pump the unevaporated refrigerant liquid of the refrigerant reservoir 271 to the refrigerant distributor 231 of the evaporator 230, the refrigerant liquid pump P is indispensable. It ends up. It will be disadvantageous in terms of cost and reliability.

FIG. 5 is a schematic view for explaining the operation of the absorption chiller 1 according to the first embodiment. As shown in FIG. 5, in the absorption chiller 1 according to the first embodiment, it is assumed that an amount of "107.5" of the refrigerant liquid flows from the condenser 20 into the refrigerant liquid pipe 61 at 40 ° C. Then, the refrigerant liquid reaches the refrigerant cooler 70 located below the evaporator 30 and exchanges heat with the unevaporated refrigerant liquid. At this time, the amount of the unevaporated refrigerant liquid of "4" is used for cooling, and the amount of the unevaporated refrigerant liquid of "2" becomes an ineffective refrigerant due to scattering or the like.

Further, the refrigerant liquid flowing from the refrigerant cooler 70 into the refrigerant liquid pipe 61 by the heat exchange is cooled to about 16 ° C. Therefore, the amount of flash vapor generated at the stage reaching the refrigerant distributor 131 is relatively small, for example, about "1.5". Therefore, the amount of flash evaporation is suppressed, the amount of the refrigerant liquid dropped on the second cold water heat transfer tube 32 increases, and the amount of the refrigerant liquid "106" is dropped. Therefore, even in a situation where a relatively large amount of the refrigerant liquid of "6" does not evaporate and becomes an unevaporated refrigerant liquid due to variations in the product, the amount of the refrigerant liquid of "100" evaporates. It becomes. That is, even in a situation where a relatively large amount of refrigerant liquid becomes an unevaporated refrigerant liquid due to variations in the product, the amount of the refrigerant liquid dropped is increasing, which can be covered and the refrigerating capacity can be improved. Can be planned. In addition, since the effective area of the second cold water heat transfer tube 32 can be expected to increase due to the decrease in flash steam, the refrigerating capacity can be improved.

Further, the absorption chiller 1 according to the first embodiment utilizes an unevaporated refrigerant liquid (for example, 6.5 ° C.) having a temperature lower than that of water in the cooling water circuit as in Patent Document 4, and is an evaporator 30. Since the refrigerant liquid flowing into the water is cooled, the flash vapor can be suppressed more effectively and the refrigerating capacity can be improved. In addition, the absorption chiller 1 according to the first embodiment can improve the refrigerating capacity without using the cold water in the second cold water heat transfer tube 32 as in Patent Document 3.

Further, even if the amount of the unevaporated refrigerant liquid increases in the absorption chiller 1 according to the first embodiment for some reason, the amount of the unevaporated refrigerant liquid accumulated in the refrigerant cooler 70 increases, and the amount of heat exchanged increases. Therefore, the temperature of the refrigerant liquid flowing into the refrigerant distributor 31 is further lowered. As a result, the amount of flash steam is further reduced, and the amount of the refrigerant liquid dropped onto the second cold water heat transfer tube 32 is increased. That is, it is possible to suppress variations in the product and reduce variations in refrigerating capacity due to machine differences.

In this way, according to the absorption type refrigerator 1 according to the first embodiment, the refrigerant liquid is dropped and evaporated to the refrigerant liquid pipe 61 for transferring the refrigerant liquid from the condenser 20 to the evaporator 30 and the second cold water heat transfer pipe 32. Since the refrigerant cooler 70 that exchanges heat with the refrigerant liquid in the refrigerant liquid pipe 61 by using the unevaporated refrigerant liquid that was not provided is provided, the refrigerant liquid is transferred from the condenser 20 to the evaporator 30 by the refrigerant liquid pipe 61. In the process, the amount of flash evaporation is suppressed at the stage where the refrigerant is cooled by the refrigerant cooler 70 and accepted by the refrigerant distributor 31 of the evaporator 30. As a result, the amount of the refrigerant liquid dropped on the second chilled water heat transfer tube 32 is increased, and the effective area of the second chilled water heat transfer tube 32 is expected to increase due to the decrease in flash steam, so that the refrigerating capacity is improved. be able to. Further, since the refrigerant liquid is transferred from the condenser 20 to the evaporator 30 by utilizing the height difference between the condenser 20 and the evaporator 30, it is not necessary to install a pump. Therefore, it is possible to improve the refrigerating capacity while preventing the cost increase and the reliability decrease due to the pump.

Further, since the amount of the ineffective refrigerant can be reduced, the heat transfer area of the evaporator 30 and the absorber 40 can be reduced to reduce the cost.

Further, a refrigerant reservoir 71 that stores the unevaporated refrigerant liquid that has been dropped on the second cold water heat transfer tube 32 and has not evaporated, and a non-evaporated portion 71 that is connected to the refrigerant liquid pipe 61 and flows and is stored in the refrigerant reservoir 71. In order to provide a heat exchange pipe 72 that is immersed in the refrigerant liquid, a refrigerant storage portion 71 such as a container for storing the unevaporated refrigerant liquid is installed under the second chilled water heat transfer pipe 32, and the refrigerant storage portion 71 is provided. The refrigerant cooler 70 can be configured by providing the heat exchange pipe 72 through which the refrigerant liquid flows, and the refrigerant cooler 70 can be realized with a relatively simple configuration.

Next, a second embodiment of the present invention will be described. The absorption chiller according to the second embodiment is the same as that of the first embodiment, but the configuration and operation are partially different. Hereinafter, the differences from the first embodiment will be described.

FIG. 6 is a schematic configuration diagram showing an absorption chiller according to the second embodiment. The absorption chiller 2 according to the second embodiment further includes a bubble pump 80. The bubble pump 80 pushes up the liquid with bubbles by utilizing the property that bubbles rise in the liquid. Some of such bubble pumps 80 send bubbles into the pump, but in the second embodiment, a configuration is adopted in which bubbles are generated in the liquid by heating and boiling.

Specifically, in the bubble pump 80, one end 81 is connected to the refrigerant reservoir 71 and the other end 82 is an open end. Such a bubble pump 80 is formed by a substantially U-shaped or substantially V-shaped pipe 83 that is convex downward, and the other end 82 is located higher than one end 81. Such a bubble pump 80 is heated when the absorption chiller 2 is stopped, and the unevaporated refrigerant liquid that has flowed into the pipe 83 from the refrigerant reservoir 71 is boiled to boil the unevaporated refrigerant liquid stored in the refrigerant reservoir 71. The refrigerant liquid is transferred from one end 81 side to the other end 82 side and discharged from the open end of the other end 82.

In particular, in the second embodiment, the bubble pump 80 is heated by using a rare solution. First, since the rare solution is heated by the regenerator 10, it is basically at a high temperature. Further, during the operation of the absorption chiller 2, the liquid level FL1 is low because the rare solution generated by the absorber 40 is sent to the regenerator 10 by the solution pump 50, but the absorption chiller 2 is stopped. Sometimes it is not necessary to feed the rare solution into the regenerator 10, and the solution pump 50 ceases to operate. Therefore, when the absorption chiller 2 is stopped, the liquid level FL2 of the high-temperature rare solution rises in the lower part of the absorber 40. In the second embodiment, the bubble pump 80 is not immersed in the rare solution when the solution pump 50 is operating, but is partially immersed in the rare solution when the solution pump 50 is stopped to be heated.

The reason for providing such a bubble pump 80 is as follows. First, when the absorption chiller 2 is stopped, the unevaporated refrigerant liquid is accumulated in the refrigerant reservoir 71. Here, when the refrigerator is stopped, the vapor pressure drops when the temperature of the rare solution drops due to the outside air temperature. Therefore, the unevaporated refrigerant liquid stored in the refrigerant reservoir 71 may self-evaporate, and the temperature may be deprived from the unevaporated refrigerant liquid and freeze. Then, at the time of freezing, the heat exchange pipe 72 and the refrigerant liquid pipe 61 may be damaged.

In order to solve such a problem, the bubble pump 80 discharges the unevaporated refrigerant liquid remaining in the refrigerant reservoir 71 to the outside of the refrigerant reservoir 71 when the refrigerator is stopped.

FIG. 7 is a cross-sectional view showing the details of the bubble pump 80 shown in FIG. As shown in FIG. 7, the bubble pump 80 has a straight pipe 84 that hangs substantially linearly from one end 81 side, and a vertical pipe that extends from the straight pipe 84 and has a higher end 82 side than one end 81 side. It is provided with a discharge pipe 85 having a slanted inclined portion 85a. Further, in the discharge pipe 85, at least a part of the inclined portion 85a is immersed in the rare solution when the solution pump 50 is stopped.

Here, in the bubble pump 80 according to the second embodiment, it is necessary to discharge the unevaporated refrigerant liquid of the refrigerant reservoir 71. Therefore, it is necessary to heat the bubble pump 80 to transfer the refrigerant liquid from one end 81 to the other end 82. However, depending on the shape of the bubble pump 80, there is a possibility that a flow of transfer from the other end 82 to one end 81 may occur.

Therefore, as shown in FIG. 7, in the second embodiment, the unevaporated refrigerant liquid in the inclined portion 85a is guided along the inclination by providing the inclined portion 85a in which the other end 82 side is higher than the one end 81 side. It is transferred to the other end 82 and discharged from the open end. Then, once the unevaporated refrigerant liquid is discharged, the unevaporated refrigerant liquid in the refrigerant reservoir 71 reaches the discharge pipe 85 through the straight pipe 84 along the flow, and the other end 82 is opened through the discharge pipe 85. It is discharged from the edge. As a result, the unevaporated refrigerant liquid is efficiently discharged.

FIG. 8 is a cross-sectional view showing a first modification of the bubble pump 80 shown in FIG. In the bubble pump 80 shown in FIG. 7, when the temperature difference between the refrigerant saturation temperature and the heating temperature is large, there is a possibility of backflow from the other end 82 to one end 81 side. Therefore, in the bubble pump 80 according to the first modification, the straight pipe 84 has a larger pipe diameter than the discharge pipe 85. As a result, the volume of the straight pipe 84 is increased and convection of the unevaporated refrigerant liquid is generated in the straight pipe 84, so that the unevaporated refrigerant liquid in the discharge pipe 85 can be preferentially heated and boiled to cause backflow. Can be prevented.

FIG. 9 is a cross-sectional view showing a second modification of the bubble pump 80 shown in FIG. In the bubble pump 80 shown in FIG. 8, when the unevaporated refrigerant liquid of the straight pipe 84 partially flows into the discharge pipe 85 due to convection and the temperature difference between the refrigerant saturation temperature and the heating temperature is large, the unevaporated refrigerant liquid is used. There was a possibility that it would be difficult to discharge. Therefore, the bubble pump 80 according to the second modification has a straight pipe 84 having a double structure. That is, the straight pipe 84 is a double composed of a first straight pipe 84a that hangs down substantially linearly from the refrigerant reservoir 71 and a second straight pipe 84b that covers the outer peripheral side of a part of the lower side of the first straight pipe 84a. It has a structure. Further, the discharge pipe 85 is connected to a position UP of the second straight pipe 84b, which is above the lower end UEP of the first straight pipe 84a.

As described above, since the straight pipe 84 has a double structure, it is difficult to heat the unevaporated refrigerant liquid in the first straight pipe 84a, and not only the unevaporated refrigerant liquid in the discharge pipe 85 but also the second straight pipe 84b The unevaporated refrigerant liquid inside can be preferentially heated and boiled. Since the discharge pipe 85 is connected to the position UP of the second straight pipe 84b that is above the lower end UEP of the first straight pipe 84a, it is heated and boiled in the second straight pipe 84b and has not evaporated. The refrigerant liquid (refrigerant vapor) can be easily guided into the discharge pipe 85. As a result, it is possible to make the structure easy to discharge while preventing backflow.

In this way, according to the absorption chiller 2 according to the second embodiment, it is possible to improve the refrigerating capacity while preventing cost increase and reliability decrease due to the pump as in the first embodiment. it can. Further, the refrigerant cooler 70 can be realized with a relatively simple configuration.

Further, according to the second embodiment, the bubble pump 80 that is heated when the refrigerator is stopped and boil the unevaporated refrigerant liquid in the pipe 83 to discharge the unevaporated refrigerant liquid stored in the refrigerant reservoir 71 is further provided. Therefore, it is possible to prevent damage to the heat exchange pipe 72 and the refrigerant liquid pipe 61 due to freezing of the unevaporated refrigerant liquid stored in the refrigerant storage portion 71.

Further, a solution pump 50 is further provided, which sends the rare solution generated by the absorber 40 during the operation of the refrigerator to the regenerator 10 and stops the operation when the refrigerator is stopped. Here, when the solution pump 50 is stopped, the rare solution is not sent to the regenerator 10, and the liquid level FL2 of the rare solution rises. As a result, the bubble pump 80, which is not immersed in the rare solution when the solution pump 50 is operated but is partially immersed in the rare solution when the solution pump 50 is stopped, can be configured, and a heater for heating or the like is required. Without having to operate the bubble pump 80, the unevaporated refrigerant solution stored in the refrigerant reservoir 71 can be discharged.

Further, the bubble pump 80 includes a straight pipe 84 and a discharge pipe 85 having an inclined portion 85a inclined so that the other end 82 side is higher than the one end 81 side, and the discharge pipe 85 is when the solution pump 50 is stopped. In, a part of the inclined portion 85a is immersed in a rare solution. Therefore, the unevaporated refrigerant liquid in the inclined portion 85a moves to the other end 82 so as to be guided along the inclination, and is discharged from the open end. Then, once the unevaporated refrigerant liquid is discharged, the unevaporated refrigerant liquid in the refrigerant reservoir 71 reaches the discharge pipe 85 through the straight pipe 84 along the flow, and the other end 82 is opened through the discharge pipe 85. It is discharged from the edge. Therefore, the unevaporated refrigerant liquid can be efficiently discharged.

Further, since the straight pipe 84 has a larger pipe diameter than the discharge pipe 85, the volume of the straight pipe 84 increases and convection of the unevaporated refrigerant liquid occurs in the straight pipe 84. The unevaporated refrigerant liquid can be preferentially heated and boiled, and the unevaporated refrigerant liquid can be discharged more efficiently.

Further, since the straight pipe 84 has a double structure including a first straight pipe 84a and a second straight pipe 84b that covers at least a part of the outer peripheral side of the first straight pipe 84a, the first straight pipe 84a The unevaporated refrigerant liquid inside is difficult to be heated, and not only the unevaporated refrigerant liquid in the discharge pipe 85 but also the unevaporated refrigerant liquid in the second straight pipe 84b can be preferentially heated and boiled. Since the discharge pipe 85 is connected to the position UP of the second straight pipe 84b that is above the lower end UEP of the first straight pipe 84a, it is heated and boiled in the second straight pipe 84b and has not evaporated. The refrigerant liquid (refrigerant vapor) can be easily guided into the discharge pipe 85. Therefore, the unevaporated refrigerant liquid can be discharged more efficiently.

Next, a third embodiment of the present invention will be described. The absorption chiller according to the third embodiment is the same as that of the first embodiment, but the configuration and operation are partially different. Hereinafter, the differences from the first embodiment will be described.

FIG. 10 is a schematic configuration diagram showing an absorption chiller according to the third embodiment. As shown in FIG. 10, the absorption chiller 3 according to the third embodiment includes a refrigerant reservoir 90 similar to the refrigerant reservoir 71 shown in the first embodiment. The refrigerant reservoir 90 is a tray-shaped container provided below the second chilled water heat transfer tube 32 and for storing the unevaporated refrigerant liquid that has not been dropped and evaporated on the second chilled water heat transfer tube 32.

Further, in the third embodiment, the absorption chiller 3 includes a second refrigerant liquid pipe 91 that connects the refrigerant reservoir 90 and the refrigerant distributor 31 of the evaporator 30. Further, in the third embodiment, the refrigerant cooler 70 is provided to exchange heat between the refrigerant liquids of the refrigerant liquid pipe 61 and the second refrigerant liquid pipe 91.

With such a configuration, the refrigerant liquid flowing through the refrigerant liquid pipe 61 is cooled by heat exchange with the unevaporated refrigerant liquid in the second refrigerant liquid pipe 91 and is supplied to the refrigerant distributor 31 of the evaporator 30.

On the other hand, the unevaporated refrigerant liquid in the second refrigerant liquid pipe 91 is heated by exchanging heat with the refrigerant liquid flowing through the refrigerant liquid pipe 61. Moreover, since the second refrigerant liquid pipe 91 is connected to the evaporator 30 and has an evaporator pressure + flow path pressure loss + pressure corresponding to the liquid depth, the boiling point of the refrigerant is about 7 ° C. or higher and 20 ° C. or lower. Therefore, the unevaporated refrigerant liquid in the second refrigerant liquid pipe 91 boils by exchanging heat with the refrigerant liquid flowing through the refrigerant liquid pipe 61. As a result, the refrigerant cooler 70 functions as a gas-liquid pump, and the unevaporated refrigerant liquid of the refrigerant reservoir 90 is transferred to the refrigerant distributor 31 of the evaporator 30.

Such transfer of the unevaporated refrigerant liquid does not require an electric pump, and the unevaporated refrigerant liquid is again supplied to the refrigerant distributor 31 of the evaporator 30 and dropped onto the second cold water heat transfer tube 32, so that the product is frozen. The ability will be further improved. In addition, in the process of transferring the unevaporated refrigerant liquid to the refrigerant distributor 31, the refrigerant liquid flowing through the refrigerant liquid pipe 61 is cooled to suppress the generation of flash steam.

In this way, according to the absorption chiller 3 according to the third embodiment, it is possible to improve the refrigerating capacity while preventing cost increase and reliability decrease due to the pump as in the first embodiment. it can.

Further, according to the third embodiment, since the refrigerant cooler 70 functions as a gas-liquid pump that boils the unevaporated refrigerant liquid stored in the refrigerant reservoir 90 and transfers it to the refrigerant distributor 31, there is no electric pump. The unevaporated refrigerant liquid can be dropped onto the second cold water heat transfer tube 32 again, and the refrigerating capacity can be further improved. Further, when the refrigerant cooler 70 functions as a gas-liquid pump, the refrigerant liquid flowing through the refrigerant liquid pipe 61 can be cooled by the refrigerant cooler 70 and sent to the refrigerant distributor 31 of the evaporator 30.

Although the present invention has been described above based on the embodiments, the present invention is not limited to the above-described embodiments, and modifications may be made without departing from the spirit of the present invention, or combinations of the respective embodiments may be made. May be good.

For example, in the first and second embodiments, the refrigerant cooler 70 is provided at the lower part of the evaporator 30, but the present invention is not particularly limited to this, and the refrigerant flowing into the evaporator 30 using the unevaporated refrigerant liquid is used. If the liquid can be cooled, it may be provided at a position other than the lower part of the evaporator 30. Further, the configuration of the refrigerant cooler 70 is not limited to the configuration including the refrigerant reservoir 71 and the heat exchange pipe 72.

Further, the heating of the bubble pump 80 according to the second embodiment is performed with a rare solution, but the present invention is not limited to this, and other heating sources may be provided. In addition, the bubble pump 80 is not limited to the structure shown in FIGS. 7 to 9.

Further, in the above embodiment, the rare solution is heated by one regenerator 10, but the present invention is not limited to this, and is composed of a plurality of regenerators 10 such as a high temperature regenerator and a low temperature regenerator. May be good. Further, in the above embodiment, other configurations such as a heat exchanger may be provided in various places.

1-3: Absorption chiller 10: Regenerator 20: Condenser 21: First cold water heat transfer tube 30: Evaporator 31: Refrigerant distributor 32: Second cold water heat transfer tube (heat transfer tube)
40: Absorber 41: Third chilled water heat transfer pipe 50: Solution pump 61: Coolant liquid pipe 62: Rare solution pipe 63: Concentrated solution pipe 70: Refrigerator cooler 71: Refrigerator reservoir 72: Heat exchange pipe 73: Inlet 74 : Outlet 75a to 75h: Straight pipe 76a to 76e: Header member 80: Bubble pump 81: One end 82: The other end 83: Piping 84: Straight pipe 84a: First straight pipe 84b: Second straight pipe 85: Discharge pipe 85a: Inclined portion 90: Refrigerator reservoir 91: Second refrigerant liquid pipe FL1: Liquid level FL2: Liquid level UEP: Lower end

Claims (5)

A regenerator that heats a rare solution to generate refrigerant vapor and a concentrated solution, a condenser that condenses the refrigerant vapor generated by the regenerator, and a cold liquid that receives the refrigerant liquid condensed by the condenser. An evaporator having a refrigerant distributor that drops the refrigerant into a flowing heat transfer tube to evaporate it, and an absorber that absorbs the refrigerant vapor evaporated by the evaporator into a concentrated solution generated by the regenerator to generate a rare solution. An absorption chiller that forms an absorption refrigeration cycle that sends the rare solution produced by the absorber to the regenerator.
A refrigerant liquid pipe that transfers the refrigerant liquid from the condenser to the evaporator by utilizing the height difference between the condenser and the evaporator, and
The unevaporated refrigerant liquid that has not been dropped and evaporated in the heat transfer tube is used to exchange heat with the refrigerant liquid in the refrigerant liquid pipe, and is provided below the heat transfer tube and dropped and evaporated in the heat transfer tube. A state in which the refrigerant reservoir for storing the unevaporated refrigerant liquid that has not been used and the inlet and outlet are both connected to the refrigerant liquid pipe to allow the refrigerant liquid to flow and to be immersed in the unevaporated refrigerant liquid stored in the refrigerant reservoir. Refrigerant cooler with heat exchange piping
When the refrigerator is stopped by the rare solution generated by the absorber, it is formed by a substantially U-shaped or substantially V-shaped pipe whose one end is connected to the refrigerant reservoir and whose other end is an open end and is convex downward. A bubble pump that is heated and boils the unevaporated refrigerant liquid in the pipe to transfer the unevaporated refrigerant liquid stored in the refrigerant reservoir from the one end side to the other end side and discharge it from the open end of the other end. When,
An absorption chiller characterized by being equipped with. Further equipped with a solution pump that sends the rare solution produced by the absorber during operation of the refrigerator to the regenerator and stops the operation when the refrigerator is stopped.
Said bubble pump, the not immersed in the diluted solution at the time of operation of the solution pump, claims, characterized in that it is configured to be heated by partially immersed in the diluted solution at the time of stopping of the solution pump The absorption chiller according to 1 . The bubble pump includes a straight pipe that hangs substantially linearly from one end side, and a discharge pipe that extends from the straight pipe and has an inclined portion inclined in the vertical direction so that the other end side is higher than the one end side. With
The absorption chiller according to claim 2 , wherein at least a part of the inclined portion of the discharge pipe is immersed in a rare solution when the solution pump is stopped. The absorption chiller according to claim 3 , wherein the straight pipe has a larger diameter than the discharge pipe. The straight pipe has a double structure including a first straight pipe that hangs down substantially linearly from the refrigerant reservoir and a second straight pipe that covers at least a part of the outer peripheral side of the first straight pipe. ,
The absorption chiller according to claim 3 , wherein the discharge pipe is connected to a position above the lower end of the first straight pipe among the second straight pipes.

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