JP7209324B2 - absorption chiller - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an absorption chiller, and more particularly to an absorption chiller capable of uniformly dispersing liquid even when the cooling load is low and improving partial load performance. .

Generally, an absorption chiller is known that includes a high-temperature regenerator, a low-temperature regenerator, an evaporator, a condenser, and an absorber, which are connected by piping to form circulation paths for the absorbent and the refrigerant, respectively. Absorption chillers are used, for example, for central air conditioning in office buildings.
Conventionally, such an absorption chiller includes pressure adjusting means and an intermediate regenerator in an absorbent solution line connecting a high temperature regenerator and a low temperature regenerator or in an absorption solution line connecting a low temperature regenerator and an absorber. The intermediate regenerator exchanges sensible and latent heat between the fluid supplied from the external heat source and the absorbent solution flowing through the absorbent solution line, and measures the cold/hot water outlet temperature and the temperature of the high temperature regenerator. It is disclosed to have a temperature measuring means and a fuel supply amount control mechanism for adjusting the amount of high quality fuel supplied to the high quality fuel combustion burner based on the hot and cold water outlet temperature and the temperature of the high temperature regenerator. (See Patent Document 1, for example).

Japanese Patent No. 3114850

Generally, in the conventional technology, an absorber or an evaporator performs heat exchange by dripping an absorption liquid or a refrigerant into a heat transfer tube installed in the absorber or evaporator. In this case, conventionally, a liquid such as an absorbing liquid is temporarily stored in a distribution box, and dripped onto the heat transfer tubes from the distribution box via a tray.
The distribution box is designed with a hole for dripping liquid based on a cooling load of 100%, so when the cooling load is high, the height of the liquid supplied to the distribution box must be adjusted appropriately. It is possible to uniformly spray the liquid on the heat transfer tubes.
However, when the cooling load is reduced to, for example, about 50%, the height of the liquid supplied to the distribution box is insufficient, resulting in a problem that uniform liquid distribution cannot be achieved. As a result, part load performance was adversely affected.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an absorption chiller capable of uniformly dispersing liquid even when the cooling load is low and improving partial load performance. It is intended to provide

In order to achieve the above object, the present invention provides a high-temperature regenerator, a low-temperature regenerator, an evaporator, a condenser, and an absorber, which are connected by piping to form circulation paths for the absorbent and the refrigerant, respectively. A type refrigerator comprising a distribution box for spraying liquid to the heat transfer tubes, the distribution box comprising a main storage box and a sub-storage box, the main storage box storing the liquid in the main storage box A communication hole is formed to supply the liquid to the sub-storage box when the liquid reaches a predetermined level, and the stored liquid drips onto the lower surface of each of the main storage box and the sub-storage box. It is characterized in that a drip hole is formed for the purpose .
According to this, when the cooling load is low, only the liquid stored in the main storage box is dripped and sprayed, and when the cooling load is high, the liquid is supplied from the main storage box to the sub-storage box through the communication hole. By sending, the liquid in the main storage box and the sub-storage box is dripped and dispersed, so the amount of liquid dripping can be adjusted according to the cooling load.

According to the present invention, the amount of liquid to be dropped can be adjusted according to the cooling load. As a result, uniform spraying according to the cooling load can be performed, and the partial load performance can be improved.

Schematic configuration diagram of an absorption chiller according to an embodiment of the present invention Schematic side view showing the structure of the absorber of the present embodiment Schematic plan view showing the structure of the absorber of the present embodiment Schematic diagram showing how the distribution box of the present embodiment is used with a low cooling load Schematic diagram showing how the distribution box of the present embodiment is used under high cooling load

A first invention is an absorption chiller comprising a high-temperature regenerator, a low-temperature regenerator, an evaporator, a condenser, and an absorber, which are connected by piping to form circulation paths for an absorption liquid and a refrigerant, respectively, A distribution box for spraying the liquid to the heat transfer tubes is provided, the distribution box includes a main storage box and a sub-storage box, and when the liquid stored in the main storage box reaches a predetermined level, the liquid to the sub-storage box.
According to this, when the cooling load is low, only the liquid stored in the main storage box is dripped and sprayed, and when the cooling load is high, the liquid is supplied from the main storage box to the sub-storage box through the communication hole. By sending, the liquid in the main storage box and the sub-storage box is dripped and dispersed, so the amount of liquid dripping can be adjusted according to the cooling load. As a result, uniform spraying according to the cooling load can be performed, and the partial load performance can be improved.

In a second aspect of the invention, a guide plate is provided above the sub-storage box and spaced apart from the communication hole by a predetermined distance.
According to this, since the guide plate is provided, it is possible to reliably prevent the liquid from splashing outside the sub-storage box when the liquid flows from the communication hole.

A third invention is a heat transfer tube provided in an absorber, and the liquid is an absorption liquid.
According to this, according to the cooling load, it is possible to adjust the dripping amount of the absorbing liquid to the heat transfer tube of the absorber, as a result, it is possible to perform uniform spraying according to the cooling load, and the partial load performance can be improved.

A fourth invention is a heat transfer tube provided in an evaporator, and the liquid is a refrigerant.
According to this, the amount of refrigerant dripping into the heat transfer tubes of the evaporator can be adjusted according to the cooling load. can be improved.

An embodiment of the present invention will be described below with reference to the drawings.
FIG. 1 is a schematic configuration diagram of an absorption chiller according to the present embodiment. The absorption refrigerator 100 is an absorption chiller-heater that uses water as a refrigerant and a lithium bromide (LiBr) aqueous solution as an absorption liquid, and heats the absorption liquid with gas fuel.

As shown in FIG. 1, the absorption refrigerator 100 includes an evaporator 1, an absorber 2 arranged in parallel with the evaporator 1, and an evaporator absorber barrel 3 housing the evaporator 1 and the absorber 2. , a high-temperature regenerator 5 equipped with a gas burner 4, a low-temperature regenerator 6, a condenser 7 arranged in parallel with the low-temperature regenerator 6, and a low-temperature regenerator condenser containing the low-temperature regenerator 6 and the condenser 7. A vessel barrel 8 is provided.
The absorption refrigerator 100 includes a low temperature heat exchanger 12, a high temperature heat exchanger 13, a refrigerant drain heat recovery device 17, a dilute absorbent pump 45, a rich absorbent pump 47, and a refrigerant pump 48. These devices are pipe-connected via absorption liquid pipes 21, 23, 24, 25 and refrigerant pipes 31, 32, 34, 35, etc. to form a circulation path.

The evaporator 1 is provided with a cold water pipe 14 for circulating and supplying the brine heat-exchanged with the refrigerant in the evaporator 1 to a heat load (for example, an air conditioner) not shown. A partially formed heat transfer tube 14A is arranged in the evaporator 1 .
The absorber 2 and the condenser 7 are provided with cooling water pipes 15 for passing cooling water through the absorber 2 and the condenser 7 in sequence. , 15B are arranged in the absorber 2 and the condenser 7 respectively.

The absorber 2 has the function of absorbing the refrigerant vapor evaporated in the evaporator 1 into the absorbing liquid and keeping the pressure inside the evaporator absorber barrel 3 in a high vacuum state. In the lower part of the absorber 2, a dilute absorbent reservoir 2A is formed in which the dilute absorbent diluted by absorbing the refrigerant vapor is stored. One end of the liquid pipe 21 is connected. The dilute absorbent pipe 21 is provided with a branched dilute absorbent pipe 21 A that branches downstream of the dilute absorbent pump 45 . The dilute absorbent pump 45 is an inverter-controllable pump, and is configured such that the drive amount of the dilute absorbent pump 45 can be varied by controlling the inverter frequency.
After passing through the refrigerant drain heat recovery device 17, the branched dilute absorbent pipe 21A joins the dilute absorbent pipe 21 again on the downstream side of the low temperature heat exchanger 12 of the dilute absorbent pipe 21. The other end of the dilute absorbent pipe 21 passes through the high-temperature heat exchanger 13 and is open to the air layer portion 5B located above the heat exchange portion 5A formed in the high-temperature regenerator 5 .
The dilute absorbent pipe 21 is branched into a second branch pipe 21B on the downstream side of the low temperature heat exchanger 12 and the second branch pipe 21B opens into the low temperature regenerator 6 .

The high-temperature regenerator 5 is configured by housing a gas burner 4 in a shell 60. A heat exchange section 5A is formed above the gas burner 4 to heat and regenerate the absorbent using the flame of the gas burner 4 as a heat source. An exhaust path 40 through which exhaust gas burned by the gas burner 4 flows is connected to the heat exchange section 5A, and an exhaust gas heat exchanger 41 is provided in the exhaust path 40 . A gas pipe 61 supplied with fuel gas and an intake pipe 63 supplied with air from a blower 62 are connected to the gas burner 4. Fuel gas and air are connected to these gas pipe 61 and intake pipe 63. A control valve 64 is provided to control the amount of A gas flow meter 65 is provided in the gas pipe 61 .

Formed on the side of the heat exchanging portion 5A is an intermediate absorbent reservoir 5C in which the intermediate absorbent flowing out of the heat exchanging portion 5A after being thermally regenerated in the heat exchanging portion 5A is accumulated. One end of a second intermediate absorbent pipe 23 is connected to the lower end of the intermediate absorbent reservoir 5C, and the second intermediate absorbent pipe 23 is provided with a high-temperature heat exchanger 13 . The high-temperature heat exchanger 13 heats the absorbent flowing through the dilute absorbent tube 21 with the heat of the high-temperature intermediate absorbent flowing out of the intermediate absorbent reservoir 5C. We are trying to reduce the amount.
The other end of the second intermediate absorbent pipe 23 is connected to a rich absorbent pipe 25 that connects the low temperature regenerator 6 and the absorber 2 . The upstream side of the high-temperature heat exchanger 13 of the second intermediate absorbent pipe 23 and the absorber 2 are connected by an absorbent pipe 24 with an on-off valve V1 interposed therebetween.

The low-temperature regenerator 6 uses the refrigerant vapor separated by the high-temperature regenerator 5 as a heat source to heat and regenerate the absorbent accumulated in the absorbent reservoir 6A formed in the low-temperature regenerator 6. , a heat transfer pipe 31A formed in a part of the refrigerant pipe 31 extending from the upper end of the high temperature regenerator 5 to the bottom of the low temperature regenerator 6 is arranged. By circulating the refrigerant vapor through the refrigerant pipe 31, the heat of the refrigerant vapor is transmitted to the absorbent accumulated in the absorbent reservoir 6A via the heat transfer pipe 31A, and the absorbent is further concentrated.
One end of a thick absorbent pipe 25 is connected to the absorbent reservoir 6A of the low-temperature regenerator 6, and the other end of the thick absorbent pipe 25 is connected to a thick liquid sprayer provided above the air layer portion 2B of the absorber 2. 2C is connected. A concentrated absorbent pump 47 and a low-temperature heat exchanger 12 are provided in the concentrated absorbent pipe 25 . The low-temperature heat exchanger 12 heats the dilute absorbent flowing through the dilute absorbent tube 21 with the heat of the concentrated absorbent flowing out of the absorbent reservoir 6B of the low-temperature regenerator 6 .

A bypass pipe 27 that bypasses the concentrated absorbent pump 47 and the low-temperature heat exchanger 12 is provided in the concentrated absorbent pipe 25 .
When the operation of the concentrated absorbent pump 47 is stopped, the absorbent accumulated in the absorbent reservoir 6A of the low temperature regenerator 6 is supplied into the absorber 2 through the concentrated absorbent pipe 25 and the bypass pipe 27 .

As described above, the gas layer portion 5B of the high-temperature regenerator 5 and the refrigerant liquid reservoir 7A formed at the bottom of the condenser 7 are connected by the refrigerant pipe 31 . The refrigerant pipe 31 includes a heat transfer pipe 31A connected to the absorbent reservoir 6A of the low-temperature regenerator 6 and a refrigerant drain heat recovery device 17. As shown in FIG. The upstream side of the heat transfer tube 31A of the refrigerant pipe 31 and the air layer portion 2B of the absorber 2 are connected by a refrigerant pipe 32 with an on-off valve V2 interposed therebetween.

One end of a refrigerant pipe 34 through which the refrigerant flowing out from the refrigerant reservoir 7A flows is connected to the refrigerant reservoir 7A of the condenser 7, and the other end of the refrigerant pipe 34 is a downwardly curved U-seal portion 34A. is connected to the gas layer portion 1A of the evaporator 1 via the .
Below the evaporator 1, a refrigerant reservoir 1B in which liquefied refrigerant is accumulated is formed. It is connected by a refrigerant pipe 35 in between.

The absorption chiller 100 of the present embodiment also includes an air bleeder 70 , and the air bleeder 70 includes a tank 71 . An air bleed pipe 72 communicating with the air layer portion 2B of the absorber 2 is connected to the upper portion of the tank 71 . A return pipe 73 that communicates with the bottom of the absorber 2 is connected to the bottom of the tank 71 . Furthermore, an absorbent pipe 75 connected to the dilute absorbent pipe 21 via an ejector pump 74 is connected to the upper portion of the tank 71 .
By driving the ejector pump 74 , the dilute absorbent in the dilute absorbent tube 21 is taken into the tank 71 through the absorbent tube 75 . The dilute absorbent flowing through the absorbent pipe 75 creates a negative pressure inside the tank 71, thereby extracting not only the non-condensable gas stored in the upper part of the absorber 2 but also the refrigerant vapor and vaporized absorbent. It is guided above the tank 71 through the trachea 72 .

Of the gas led to the tank 71, the refrigerant vapor and the vaporized absorbing liquid are absorbed by the absorbing liquid accumulated in the lower part of the tank 71. It is stored above the tank 71 . Then, the absorbent accumulated in the lower part of the tank 71 is returned to the absorber 2 through the return pipe 73 .

Next, the structure of the absorber of this embodiment will be described.
FIG. 2 is a schematic side view showing the structure of the absorber. FIG. 3 is a schematic plan view showing the structure of the absorber. FIG. 4 is a schematic diagram showing how the distribution box is used with a low cooling load. FIG. 5 is a schematic diagram showing how the distribution box is used with a high cooling load.
As shown in FIGS. 2 and 3, inside the absorber 2, a large number of heat transfer tubes 15A are arranged. Cooling water is passed through the inside of the heat transfer tube 15A. The heat transfer tubes 15A are formed so as to meander by folding back at the ends, and are configured such that a plurality of heat transfer tubes 15A are arranged in the vertical and horizontal directions.

A plurality of lower trays 51 are arranged above the heat transfer tubes 15A. The lower tray 51 is configured to extend in the depth direction in FIG.
A plurality of (three in the present embodiment) upper trays 53 extending in a direction orthogonal to the lower tray 51 are arranged above the lower tray 51 . The upper trays 53 are arranged to extend in the horizontal direction in FIG. 2, and are arranged at predetermined intervals in the horizontal direction in FIG. The lower surface of the upper tray 53 is formed with a dripping hole 54 for dripping the absorbing liquid dripped onto the upper tray 53 onto the lower tray 51 .

A distribution box 55 is arranged above the upper tray 53 . The distribution box 55 is composed of a main storage box 56 to which the absorbent is sent and a sub-storage box 57 integrally attached to one side of the main storage box 56 . Two dripping holes 58 are formed in the lower surface of the main storage box 56 , and one dripping hole 59 is formed in the lower surface of the sub-storage box 57 .

A communication hole 80 communicating with the sub-storage box 57 is formed in the upper side of the main storage box 56 . The communication hole 80 is provided at a predetermined height from the bottom surface of the main storage box 56 . That is, when the absorbent is supplied to the main storage box 56 , the absorbent is dripped onto the upper tray 53 through the drip hole 58 of the main storage box 56 until the water level of the absorbent reaches the communication hole 80 .
Then, when the water level of the absorbent reaches the communication hole 80 , part of the absorbent stored inside the main storage box 56 is sent to the sub-storage box 57 via the communication hole 80 . In this state, the absorbent is dripped onto the upper tray 53 from both the drip hole 58 of the main storage box 56 and the drip hole 59 of the sub-storage box 57, thereby increasing the drip amount of the absorbent. becomes possible.

Above the sub-storage box 57, an upper plate 81 covering part of the upper surface of the sub-storage box 57 is arranged so as to extend downward from the tip of the upper plate 81 and face the communication hole 80. A guide plate 83 is provided which consists of a side plate 82 which
The guide plate 83 is arranged at a predetermined distance from the communication hole 80 and prevents splashing of the absorbent sent from the main storage box 56 to the sub-storage box 57 through the communication hole 80 .

Next, the operation of this embodiment will be described.
During cooling operation, brine (for example, cold water) is circulated and supplied to a heat load (not shown) through the cold water pipe 14 .
In this case, the lean absorbent from the absorber 2 is heated by the lean absorbent pump 45 via the lean absorbent tube 21 via the low temperature heat exchanger 12 and the high temperature heat exchanger 13 or the exhaust gas heat exchanger 41. It is sent to the high temperature regenerator 5 .
The absorbent sent to the high-temperature regenerator 5 is heated by the flame from the gas burner 4 and the high-temperature combustion gas in the high-temperature regenerator 5, so that the refrigerant in the absorbent evaporates and separates. The intermediate absorbent whose concentration has increased by evaporating and separating the refrigerant in the high-temperature regenerator 5 is sent to the concentrated absorbent pipe 25 via the high-temperature heat exchanger 13 and joins the absorbent that has passed through the low-temperature regenerator 6. .

On the other hand, the absorbent sent to the low-temperature regenerator 6 is heated by the high-temperature refrigerant vapor that is supplied from the high-temperature regenerator 5 through the refrigerant pipe 31 and flows into the heat transfer pipe 31A. This concentrated absorbent is combined with the absorbent that has passed through the high-temperature regenerator 5, and is sent to the absorber 2 via the low-temperature heat exchanger 12 by the concentrated absorbent pump 47, whereupon it is sent to the concentrated liquid sprayer 2C. distributed from.

The refrigerant separated and produced by the low-temperature regenerator 6 enters the condenser 7, is condensed, and accumulates in the refrigerant liquid reservoir 7A. When a large amount of refrigerant liquid accumulates in the refrigerant liquid reservoir 7A, this refrigerant liquid flows out from the refrigerant liquid reservoir 7A, enters the evaporator 1 via the refrigerant pipe 34, is pumped by the operation of the refrigerant pump 48, and is dispersed. It is sprayed from the vessel 1C onto the heat transfer tubes 14A of the cold water tubes 14.
Since the refrigerant liquid sprayed over the heat transfer tubes 14A takes the heat of vaporization from the brine passing through the heat transfer tubes 14A and evaporates, the brine passing through the heat transfer tubes 14A is cooled, and the brine whose temperature has been lowered in this way is cooled. Cooling operation such as cooling is performed by supplying the heat load from the cold water pipe 14 .
The refrigerant evaporated in the evaporator 1 enters the absorber 2 and is absorbed by the concentrated absorbent supplied from the low-temperature regenerator 6 and sprayed from above. The circulation of the absorbent pump 45 to the high-temperature regenerator 5 is repeated.

In the present embodiment, when the absorbent is supplied to the distribution box 55 in the absorber 2 , the absorbent is stored in the main storage box 56 . In this case, if the cooling load is lower than 50%, for example, as shown in FIG. will be
The absorbent in the main storage box 56 is dripped onto the upper tray 53 through the drip hole 58 and then dripped from the upper tray 53 onto the lower tray 51 through the drip hole 54 . The absorbent dripped onto the lower tray 51 is dripped from the lower tray 51 to the heat transfer tubes 15A via the drip holes 52 and sprayed.

Also, when the cooling load exceeds, for example, 50%, the amount of the absorbent supplied to the main storage box 56 increases, so that the water level of the absorbent reaches the communication hole 80 . Therefore, as shown in FIG. 5, part of the absorbent stored in the main storage box 56 flows through the communication hole 80 to the sub-storage box 57 .
At this time, since the guide plate 83 is provided, it is possible to reliably prevent the absorbent from scattering outside the sub-storage box 57 when the absorbent flows through the communication hole 80 .

The absorbent stored in the main storage box 56 and the sub-storage box 57 is dripped onto the upper tray 53 via the drip holes 58 and 59, respectively. Thereafter, the absorbent is similarly sprayed from the upper tray 53 through the lower tray 51 to the heat transfer tubes 15A. As a result, the absorbent is dripped from the main storage box 56 and the sub-storage box 57, so that the drip amount of the absorbent can be increased.
As described above, in the present embodiment, the drip amount of the absorbent can be adjusted according to the cooling load, and uniform spraying according to the cooling load can be performed.

As described above, in the present embodiment, the high-temperature regenerator 5, the low-temperature regenerator 6, the evaporator 1, the condenser 7 and the absorber 2 are provided, and these are connected by piping to form a circulation path for the absorbent and the refrigerant. and a distribution box 55 for spraying the absorbing liquid (liquid) on the heat transfer tubes 15A. The distribution box 55 includes a main storage box 56 and a sub storage box 57, and A communicating hole 80 is formed to supply the absorbent to the sub-storage box 57 when the absorbent in the container reaches a predetermined level.
According to this, when the cooling load is low, only the absorbent stored in the main storage box 56 is dripped and sprayed, and when the cooling load is high, the sub storage is carried out from the main storage box 56 via the communication hole 80. By sending the absorbing liquid to the box 57, the absorbing liquid in the main storage box 56 and the sub-storage box 57 is dripped and dispersed, so that the amount of dripping of the absorbing liquid can be adjusted according to the cooling load. As a result, uniform spraying according to the cooling load can be performed, and the partial load performance can be improved.

Further, in this embodiment, a guide plate 83 is provided above the sub-storage box 57 with a predetermined distance from the communication hole 80 .
According to this, since the guide plate 83 is provided, it is possible to reliably prevent the absorbent (liquid) from scattering outside the sub-storage box 57 when the absorbent (liquid) flows from the communication hole 80 . .

In addition, this embodiment shows one aspect|mode to which this invention is applied, Comprising: This invention is not limited to the said embodiment.
For example, in the present embodiment, an example of a case where the absorption liquid is sprayed as a liquid on the heat transfer tubes 15A of the absorber 2 is shown, but for example, when the refrigerant is sprayed as a liquid on the heat transfer tubes 14A of the evaporator 1 may be applied to

In addition, although the configuration provided with the gas burner 4 for heating by burning the fuel gas as a heating means for heating the absorbent in the high-temperature regenerator 5 has been described, the present invention is not limited to this. may be provided with a gas burner for burning, or may be heated using heat such as steam or exhaust gas.

Reference Signs List 1 evaporator 2 absorber 4 gas burner 5 high temperature regenerator 6 low temperature regenerator 7 condenser 51 lower tray 52, 54, 58, 59 drip hole 53 upper tray 55 distribution box 56 main storage box 57 sub-storage box 70 extraction device 80 Communication hole 81 Upper plate 82 Side plate 83 Guide plate 100 Absorption chiller

Claims (6)

An absorption chiller comprising a high-temperature regenerator, a low-temperature regenerator, an evaporator, a condenser, and an absorber, which are connected by piping to form circulation paths for the absorbing liquid and the refrigerant, respectively,
Equipped with a distribution box for spraying liquid on the heat transfer tubes,
The distribution box includes a main storage box and a sub-storage box, and the main storage box supplies the liquid to the sub-storage box when the liquid stored in the main storage box reaches a predetermined level. A communicating hole is formed to supply
An absorption chiller, wherein a drip hole for dripping the liquid to be stored is formed in the lower surface of each of the main storage box and the sub-storage box. 2. The absorption chiller according to claim 1, further comprising a guide plate disposed above said sub-storage box with a predetermined distance from said communication hole. A guide plate is provided above the sub-storage box for preventing the liquid from splashing outside the sub-storage box when the liquid flows from the communication hole. 2. The absorption chiller according to 1. 4. The absorption refrigeration system according to any one of claims 1 to 3, wherein when the cooling load exceeds a predetermined value, the water level of the liquid stored in the main storage box reaches the communication hole. machine. 5. The absorption chiller according to any one of claims 1 to 4, wherein the heat transfer tube is a heat transfer tube provided in an absorber, and the liquid is an absorption liquid . The absorption chiller according to any one of claims 1 to 4, wherein the heat transfer tube is a heat transfer tube provided in an evaporator, and the liquid is a refrigerant .

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