JP2877560B2 - Low temperature regenerator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a low-temperature regenerator for heating an absorbing liquid with a refrigerant vapor to separate the refrigerant vapor from the absorbing liquid.

[0002]

2. Description of the Related Art For example, Japanese Patent Application Laid-Open No. 1-234765 discloses that an intermediate absorbing liquid sent from a high-temperature regenerator through a high-temperature heat exchanger is heated by a heater through which refrigerant vapor flows from the high-temperature regenerator. An absorption refrigerator having a low-temperature regenerator that further separates refrigerant vapor from the intermediate absorption liquid and sends the concentrated absorption liquid to the absorber is disclosed. Since the pressure of the high-temperature regenerator is much higher than that of the low-temperature regenerator, the pressure difference causes the intermediate absorbent to flow from the high-temperature regenerator to the low-temperature regenerator.

[0003]

In the above-mentioned conventional technology, the heat transfer in the low-temperature regenerator generally includes boiling heat transfer and convective heat transfer. In the conventional low-temperature regenerator, the vicinity of the heat transfer tube constituting the heater is known. The convection heat transfer has a low heat transfer characteristic corresponding to free convection heat transfer because the flow of the absorbing liquid is slow.
Furthermore, since there is no air bubble at the bottom of the low-temperature regenerator near the heat transfer tube, the flow of the absorbing liquid is insufficient, the liquid temperature rises, and the heat transfer effect decreases.

[0004] In particular, when the heat transfer on the outer surface of the heat transfer tube of the low-temperature regenerator is low, there arises a problem that the amount of heat exchange becomes insufficient and the heat concentration of the absorbing solution becomes insufficient. Further, when the heat transfer area is increased to increase the amount of heat exchange, there is a problem that the low-temperature regenerator becomes large.

An object of the present invention is to increase the heat exchange amount of a low-temperature regenerator to achieve high performance and to reduce the size of the low-temperature regenerator.

[0006]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a plurality of heat transfer tubes 10 through which high-temperature steam flows.
And a low-temperature regenerator including an inlet 14 for the intermediate absorbing liquid and an outlet 16 for the concentrated absorbing liquid, from almost the middle between the inlet 14 and the outlet 16 to the vicinity of the inlet 14, And a low-temperature regenerator provided with a circulating pipe 18 for returning the intermediate absorbent to the vicinity of the inlet 14 and an absorbent pump 21 provided in the circulating pipe 18. It aims at miniaturization and miniaturization.

A closed heat exchanger 30 provided on the inlet 26 side of the intermediate absorbent, an open low-temperature regenerator 31 provided on the outlet 16 side of the concentrated absorbent, Low-temperature regeneration comprising a circulation pipe 27 for the intermediate absorption liquid extending from substantially the middle of the inlet 26 and the outlet 16 for the concentrated absorption liquid to the closed low-temperature regenerator 30, and an absorption pump 21 provided in the circulation pipe 27. A low-temperature regenerator with high performance and miniaturization.

[0008]

By the operation of the absorbent pump 21, the intermediate absorbent flows through the circulation pipe 18, flows into the regenerator from the vicinity of the inlet port 14, and flows from the inlet port 14 side by the intermediate absorbent flowing from the circulation pipe 18. The flow of the intermediate absorbent flowing toward the outlet 16 becomes faster, the forced convection heat transfer becomes active, and the heat transfer tube 10
And the amount of heat exchange from the medium to the intermediate absorbing liquid increases, so that the regenerator can have higher performance and smaller size.
Further, since the circulation pipe 27 is provided independently, it is possible to prevent the intermediate absorbing liquid flowing from the inlet 14 at the time of partial load from being affected by the intermediate absorbing liquid sent by the operation of the absorbing liquid pump 21. Also at the time of load, the absorbent pump 21 can be operated in the same manner as at the time of full load to circulate the intermediate absorbent, and the operating efficiency at the time of partial load can be improved.

Further, the discharge pressure of the absorbing liquid pump 21 and the pressure of the intermediate absorbing liquid flowing from the inlet 26 directly act on the intermediate absorbing liquid of the closed low-temperature regenerator 30 and flow from the inlet 26 to the outlet 16. The flow of the flowing intermediate absorption liquid is greatly increased,
Heat transfer on the outer surface of the heat transfer tube 10 is promoted. For this reason, the amount of heat exchange is greatly increased, and it is possible to improve the performance and the size of the low-temperature regenerator. Further, by independently connecting the circulation pipe 27 to the low-temperature regenerator, it is possible to prevent the intermediate absorbent flowing from the inlet 26 at the time of partial load from being affected by the intermediate absorbent supplied by the operation of the absorbent pump 21. However, the flow of the intermediate absorbent in the hermetic low-temperature regenerator 30 is increased by the discharge pressure of the absorbent pump 21, and the amount of heat exchange is increased, so that the operating efficiency under a partial load can be improved.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below in detail with reference to the drawings. FIG. 1 shows a low-temperature regenerator 1 provided in, for example, an absorption refrigerator, 2 is a body, 3 and 4 are tube sheets,
5 is a refrigerant vapor inlet side header, 6 is a refrigerant vapor inlet, 7 is a refrigerant drain outlet side header, 8 is a refrigerant drain outlet, and the inside of the low temperature regenerator 1 is configured as an open type low temperature regenerator. 1
Reference numerals 0... Represent heat transfer tubes, and each of the heat transfer tubes 10 is provided between the tube sheet 3 and the tube sheet 4 in a plurality of stages and in a plurality of rows horizontally. Reference numerals 11 and 12 denote pipe supports, and the pipe sheets 3 and 4
Are provided between them.

Reference numeral 13 denotes an intermediate absorption liquid pipe connected to the low-temperature regenerator 1, and the intermediate absorption liquid pipe 13 is connected to a high-temperature heat exchanger (not shown). Reference numeral 14 denotes an inflow port of the intermediate absorbent provided at one end in the low-temperature regenerator 1, and the inflow port 14 faces the other end of the low-temperature regenerator 1. Reference numeral 15 denotes a concentrated absorption liquid outlet box provided at the other end of the low-temperature regenerator 1;
Is a concentrated absorbent outlet, and 17 is a concentrated absorbent tube. Reference numeral 18 denotes a circulation pipe for the intermediate absorbent. One end of the circulation pipe 18 is connected to a substantially middle portion between the inlet 14 and the outlet 16, that is, to a substantially middle bottom of the low-temperature regenerator 1. Reference numeral 20 is provided near the inlet 14. The inflow port 20 faces the flow direction of the absorbent like the inflow port 14. An absorbent pump 21 is provided in the middle of the circulation pipe 18. Reference numeral 22 denotes a partition plate provided in a space on the intermediate absorption liquid inflow side in the low temperature regenerator 1, and reference numeral 23 denotes an eliminator.

During operation of the absorption refrigerator, an intermediate absorbent, for example, an aqueous solution of lithium bromide, flows from a high-temperature regenerator (not shown) through a high-temperature heat exchanger and an intermediate absorbent pipe 13 to an inlet 14.
From the low-temperature regenerator 1. Here, the intermediate absorbent flows in the direction of the outlet 16. Further, the refrigerant vapor separated from the rare absorbing liquid in the high-temperature regenerator flows into the refrigerant vapor inlet side header 5 from the refrigerant vapor inlet 6. Then, the refrigerant vapor flows in each heat transfer tube 10 toward the refrigerant drain outlet side header. Also, the operation of the absorbent pump 21 causes the low-temperature regenerator 1 to operate.
Flows through the circulation pipe 18 and flows into the low-temperature regenerator 1 from the inlet 20. The intermediate absorbing liquid flowing from the inlet 20 flows in the direction of the outlet 16 together with the intermediate absorbing liquid flowing from the inlet 14. For this reason, the flow of the intermediate absorbing liquid from the inlet 14 side of the low-temperature regenerator 1, that is, from one end to the outlet 16 side, that is, the other end direction becomes faster, and the heat transfer tube 10
The flow of the intermediate absorbing liquid flowing on the outer surface of the liquid becomes faster.

The intermediate absorbent flowing into the low-temperature regenerator 1 from the inlet 14 and the inlet 20 and flowing toward the outlet 16 is heated by the heat transfer tubes 10 through which the refrigerant vapor flows. Then, the refrigerant vapor is separated from the intermediate absorbing liquid, and the concentrated absorbing liquid having a higher concentration flows out of the outlet 16 into the concentrated absorbing liquid pipe 17 and flows to the absorber (not shown).

When the absorption chiller is partially loaded and the flow rate of the intermediate absorption liquid flowing through the intermediate absorption liquid pipe 13 is low and the flow rate is small, the operation of the absorption liquid pump 21 allows the intermediate absorption liquid to be discharged. It flows into the low-temperature regenerator 1 from the inlet 20.
For this reason, the flow speed of the intermediate absorbing liquid flowing from the inlet 14 to the outlet 16 is substantially equal to that of the absorption refrigerator at full load.

According to the above embodiment, the operation of the absorbent pump 21 causes the intermediate absorbent, which is substantially at the center of the absorption refrigerator 1, to flow into the low-temperature regenerator 1 from the inlet 20 at one end. The flow of the intermediate absorbent flowing from the inlet 20 toward the outlet 16 becomes faster, and forced convection heat transfer becomes active. As a result, the amount of heat transfer from each heat transfer tube 10 to the intermediate absorbent increases, the amount of heat exchange increases, and the low-temperature regenerator 1
Of the low-temperature regenerator 1 can be downsized. And the filling amount of the absorbing liquid can be reduced by downsizing the low-temperature regenerator 1. In addition, by forcibly flowing the intermediate absorbent, the heat-concentrated absorbent in the vicinity of the heat transfer tube 10 is strongly replaced with an unabsorbed absorbent, thereby avoiding a local rise in temperature and concentration. Can be.

Also, when the absorbent pump 21 is operated at the time of partial load, the intermediate absorbent flows into the low-temperature regenerator 1 from the inflow port 20 through the circulation pipe 18 by the discharge pressure of the absorbent pump 21. Even when the amount of the intermediate absorbing liquid flowing from the inlet 14 is reduced, it is possible to prevent the flow velocity of the intermediate absorbing liquid flowing toward the outlet 16 from drastically lowering, to secure the heat exchange amount, and to operate at the partial load. Efficiency can be improved. Further, since the circulating pipe 18 provided with the absorbent pump 21 is provided in the low-temperature regenerator 1 independently of the intermediate absorbent pipe 13, the discharge pressure of the absorbent pump 21 is reduced during partial load. The influence on the intermediate absorbing liquid flowing through the pipe 13 from the outlet 14 can be avoided. As a result, there is no need to provide a damper or the like for adjusting the flow rate in the circulation path 18,
At the time of partial load, the absorbent pump 21 can be operated in the same manner as at full load to circulate the intermediate absorbent, and as a result,
The operating efficiency at the time of partial load can be further improved.

Hereinafter, a second embodiment of the present invention will be described with reference to FIG. 2, the same components as those in FIG. 1 are denoted by the same reference numerals, and detailed description thereof will be omitted.

In FIG. 2, reference numeral 24 denotes a partition plate. The partition plate 24 is provided at substantially the same position as the level of the intermediate absorbing liquid on the intermediate absorbing liquid inflow side in the low-temperature regenerator 1. And
The intermediate absorbent tube 25 extends into the low-temperature regenerator 1 from the upper wall on the tube plate 4 side of the body 2, and the inlet 26 at the tip is open to the lower surface of the partition plate 24. The circulation pipe 27 extends into the low-temperature regenerator 1 from the upper wall of the vessel body 2 on the side of the tube plate 4, similarly to the intermediate absorption liquid pipe 13. . The closed low-temperature regenerator 30 is located below the partition plate 24.
An open low-temperature regenerator 31 whose absorption liquid surface is not covered by the partition plate 24 is formed on the outflow port 16 side of the partition plate 24.

During operation of the absorption refrigerator, the intermediate absorption liquid pipe 25
Flows into the closed low-temperature regenerator 30 through the inlet 26. In addition, the operation of the absorbent pump 21 causes the intermediate absorbent in the intermediate portion of the low-temperature regenerator 1 to flow through the circulation pipe 27, and flows into the closed low-temperature regenerator 30 through the inlet 28.
The intermediate absorbent flowing into the closed low-temperature regenerator 30 from the inlet 26 and the inlet 28 flows toward the outlet 16 while being heated by the respective heat transfer tubes 10 by forced convection transfer. Here, in the closed type low temperature regenerator 30, the absorbent pump 2
Since there is no escape for the pump pressure of 1 and the pressure of the high-temperature regenerator, each pressure acts directly on the intermediate absorbent in the closed low-temperature regenerator 30, and the flow of the intermediate absorbent is fast. Therefore, the flow of the intermediate absorbent flowing into the open-type low-temperature regenerator 34 is fast,
The amount of heat exchange in the open type low-temperature regenerator 34, which is a region for boiling, is greatly increased.

Further, even when the outflow pressure of the intermediate absorbing liquid from the outlet 26 at the time of the partial load is small, the escape area of the discharge pressure of the intermediate absorbing liquid from the absorbing liquid pump 21 is not the closed low-temperature regenerator 30, so that the intermediate absorbing liquid is not absorbed. The liquid flow is fast and the amount of heat exchange increases.

According to the above embodiment, the discharge pressure of the absorbing liquid pump 21 and the pressure of the intermediate absorbing liquid flowing through the intermediate absorbing liquid pipe 25 directly act on the intermediate absorbing liquid of the closed type low temperature regenerator 30. The flow of the intermediate absorbent flowing from the inlet 26 and the inlet 28 to the open-type low-temperature regenerator 34 can be greatly increased, the forced convection heat transfer is greatly increased, and the open-type low-temperature regenerator is further improved. The flow of the intermediate absorbing liquid flowing through the heat transfer tube 31 can be increased, and the heat transfer on the outer surface of the heat transfer tube 10 is promoted by the forced convection heat transfer. As a result, the amount of heat exchange is greatly increased, and high performance and small size in the low temperature regenerator 1 can be achieved. Also, the forced convection of the intermediate absorbing liquid further promotes the replacement of the heated and concentrated absorbing liquid near the heat transfer tube with the non-absorbed absorbing liquid, thereby avoiding a local temperature or concentration increase.

Further, even at the time of partial load, the intermediate absorbing liquid flows into the closed low-temperature regenerator 30 from the inlet 26 due to the discharge pressure of the absorbing liquid pump 21. Acts directly on the intermediate absorbent in the heat exchanger 30 to speed up the flow of the intermediate absorbent and the flow of the intermediate absorbent in the open-type low-temperature regenerator 31, increase the heat exchange by forced convection heat transfer, and increase the partial load. The operating efficiency at the time is improved.

Further, since the intermediate absorption liquid pipe 25 and the circulation pipe 27 are separately connected to the low-temperature regenerator 1, at the time of partial load,
It is possible to prevent the discharge pressure of the absorbent pump 21 from affecting the intermediate absorbent flowing through the intermediate absorbent pipe 25. Even when the partial load is applied, the absorbent pump 21 is kept in a closed low-temperature It can be sent to the regenerator 30, and as a result, the operating efficiency under partial load can be further improved.

[0024]

According to the present invention, there is provided a low-temperature regenerator configured as described above. The low-temperature regenerator is configured to flow the intermediate absorbing liquid from substantially the middle between the inlet of the intermediate absorbing liquid and the outlet of the concentrated absorbing liquid to the vicinity of the inlet. A circulation pipe for the intermediate absorbent returning to the vicinity of the inlet was provided, and the absorbent pump was provided in this circulation pipe, so that the intermediate absorbent was discharged from the circulation pipe by the operation of the absorbent pump, and from the inlet side of the low-temperature regenerator. The flow rate of the intermediate absorbent flowing toward the outlet can be increased, the amount of heat transferred from the heat transfer tube to the intermediate absorbent increases, and the performance and size of the low-temperature regenerator can be improved. Further, at the time of partial load, the intermediate absorbent at the intermediate portion of the low-temperature regenerator can be sent to the inlet of the low-temperature regenerator through the circulation pipe without affecting the intermediate absorbent flowing from the inlet. The absorbing liquid can be smoothly sent to the low-temperature regenerator, and can be sent from the circulation pipe to the low-temperature regenerator. As a result, the amount of heat exchange at the time of partial load can be secured and the operation efficiency can be improved.

Further, a closed low-temperature regenerator is formed on the inlet side of the intermediate absorbent, and an open low-temperature regenerator is formed on the outlet side of the concentrated absorbent. A circulating pipe for the intermediate absorbing liquid from almost the middle to the outlet to the closed low-temperature regenerator, and an absorbing liquid pump provided in the circulating pipe,
The discharge pressure of the absorption pump and the pressure of the intermediate absorption liquid flowing through the intermediate absorption liquid pipe directly act on the intermediate absorption liquid of the closed-type low-temperature regenerator to further speed the flow of the intermediate absorption liquid of the low-temperature regenerator. Therefore, the amount of heat exchange can be greatly increased, and the performance and size of the low-temperature regenerator can be improved. Also, at the time of partial load, the discharge pressure of the intermediate absorbent by the operation of the absorbent pump flows to the closed low-temperature regenerator without affecting the intermediate absorbent flowing through the intermediate absorbent pipe. Due to the pressure of the intermediate absorbing liquid flowing through the tube, the flow of the intermediate absorbing liquid flowing through the closed low-temperature regenerator is increased, and the amount of heat exchange can be secured to improve the operation efficiency.

[Brief description of the drawings]

FIG. 1 is a partially cutaway front view of a low-temperature regenerator.

FIG. 2 is a partially cutaway front view of a low-temperature regenerator including a closed-type low-temperature regenerator.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Low-temperature regenerator 10 Heat transfer pipe 14 Inflow port of intermediate absorption liquid 16 Outflow port of concentrated absorption liquid 18 Circulation pipe 21 Absorption liquid pump

Claims (2)

(57) [Claims] 1. A low-temperature regenerator accommodating a plurality of heat transfer tubes through which high-temperature steam flows and having an inlet for an intermediate absorbing liquid and an outlet for a concentrated absorbing liquid, wherein the inlet and the outlet are connected to each other. A regenerator comprising: a circulating pipe for an intermediate absorbing liquid which is substantially at the middle to the vicinity of the inlet and returns the intermediate absorbing liquid to the vicinity of the inlet; and an absorbent pump provided in the circulating pipe. 2. A plurality of heat transfer tubes, through which high-temperature steam flows, are provided. The heat transfer tubes include an inlet for the intermediate absorbing solution and an outlet for the concentrated absorbing solution. A low-temperature regenerator for heating to separate refrigerant vapor, wherein a closed low-temperature regenerator provided on the inlet side of the absorbent, an open-type low-temperature regenerator provided on the outlet side of the absorbent, Low-temperature regeneration characterized by comprising a circulating pipe for an intermediate absorbing liquid extending from substantially the middle of the inlet and the outlet of the absorbing liquid to a closed low-temperature regenerator, and an absorbing pump provided in the circulating pipe. vessel.