JP2522965B2 - Absorber - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention cools the outside of a heat transfer tube with a cooling medium such as air, and causes an absorbing liquid to flow down along an inner wall surface of the heat transfer tube, thereby causing a gaseous refrigerant inside the tube to flow. The present invention relates to an improvement of an absorber having a structure for absorbing water.

(B) Conventional technology The absorber configured as described above absorbs the refrigerant by forming a thin liquid film of the absorbing liquid flowing down along the inner wall surface of the heat transfer tube to increase the contact area between the absorbing liquid and the gaseous refrigerant. The capacity is secured, and the lower the heat transfer tube, the thicker the liquid film of the absorbing liquid that has absorbed the refrigerant, and the weaker the refrigerant absorbing capacity. There is also a limit to the length of the heat transfer tube on which the liquid film is formed, and beyond this, the refrigerant absorbing ability of the absorbing liquid is hardly exhibited. In addition, since the length of the heat transfer tube is limited, the heat exchange area between the cooling medium outside the heat transfer tube and the heat transfer tube is also limited. There is also a drawback that it is difficult to improve the refrigerant absorption capacity of the container.

Therefore, as a conventional technique of the above-mentioned type of absorber proposed in order to reduce these drawbacks, for example, as shown in Japanese Utility Model Publication No. 56-92063, a plurality of heat transfer tubes having a predetermined length are provided. Arranged in parallel, each of these heat transfer tubes is sprayed with a concentrated absorption liquid with strong refrigerant absorption from the generator side to make the absorption liquid flow down along the inner wall surface of the tubes to absorb the refrigerant. There is an air-cooled absorber having a structure in which the rare absorbent flowing down to the bottom of the is collected in a liquid reservoir and the collected rare absorbent is returned to the generator side.

(C) Problems to be Solved by the Invention In the conventional air-cooled absorber described above, although there is an advantage that the heat exchange area between the heat transfer tube and the air for cooling the absorbing liquid can be sufficiently increased, It was confirmed by experiments that there is a problem that the concentration of the collected rare absorbing liquid is high and the degree of absorption of the refrigerant by the absorbing liquid is small. For example, in a conventional air-cooled absorber, the concentration in each heat transfer tube
5% from the evaporator by spraying 60% lithium bromide aqueous solution
As a result of an experiment to absorb water vapor at about 6 ° C, the concentration of the lithium bromide aqueous solution flowing down into the liquid reservoir of the absorber was about 59%, and the concentration difference between the concentrated absorbing liquid and the diluted absorbing liquid was about 1%. I knew it was. It is generally known that in the well-known shell-and-tube type water-cooled absorber, the difference in concentration between the concentrated absorbent and the diluted absorbent is about 3 to 4%,
Compared with the refrigerant absorption capacity of this shell-and-tube type water-cooled absorber, that of the conventional air-cooled absorber is about 1/4 to 1/3, which is much lower. It was also found that this is a major factor that hinders the practical use of the air-cooled absorber.

In view of such problems, the present invention aims to increase the refrigerant absorption capacity of the absorber having the above-described configuration to the same extent as that of the shell-and-tube type water-cooled absorber, and also has an air-cooled type with a simple structure. The purpose is to put the absorber into practical use.

(D) Means for Solving the Problems As a means for solving the above problems, the present invention forms a heat transfer tube group having a common liquid reservoir except at least the last row of heat transfer tubes of the absorber, and A heat transfer tube group and a heat transfer tube that does not have a common liquid reservoir are connected in series with an absorption liquid flow path, while at least the frontmost heat transfer tubes of the above heat transfer tube group are all or partly absorbed with a pump. The liquid recirculation path is provided.

(E) Action In the absorber of the present invention, the concentration of this absorbing liquid and the concentration of the concentrated absorbing liquid flowing into the absorber are obtained by repeatedly absorbing the refrigerant in the absorbing liquid in the heat transfer tube provided with the absorbing liquid reflux passage. 3-4 difference
% Or more, there is a difference in concentration between the dilute absorption liquid and the concentrated absorption liquid that is returned from the liquid reservoir of the heat transfer tube group equipped with the absorption liquid return path to the generator side via the last row of heat transfer tubes. Can be about 3-4% or more.

As a result, even in the air-cooled absorber using the outside air having a higher temperature level than the cooling water as the cooling medium of the absorber,
For example, it is possible to exhibit the same or higher refrigerant absorption capacity as the shell-and-tube type water-cooled absorber.

(F) Embodiments The drawings are schematic configuration diagrams showing an embodiment of the air-cooled absorber according to the present invention. In Fig. 1, (A ₁ ),
(A ₂ ), (A ₃ ), and (A ₄ ) are heat transfer tubes of a predetermined length for the absorber, which are vertically arranged and have a vapor phase portion above them and an evaporator (not shown). And) is a duct (D)
Connected by. (1), (2), (3) and (4) are liquid sprayers provided on top of the heat transfer tubes (A ₁ ), (A ₂ ), (A ₃ ), and (A ₄ ), respectively. The liquid sprayer (1) in the front row and the generator (not shown) side are connected by a concentrated absorbent liquid pipe (T _H ), while the bottom of the heat transfer tubes (A ₄ ) in the last row and the generator side absorbing liquid between the absorber and the generator are connected by a pump rare absorption liquid (P _L) with a conduit (T _L) is circulated to the. Further, (S) is a common liquid reservoir to which the heat transfer tubes (A ₁ ) in the front row, the heat transfer tubes in the second row (A ₂ ) and the heat transfer tubes in the third row (A ₃ ) are connected. A heat transfer tube group is formed by these heat transfer tubes through the reservoir.

The reservoir (S) and the liquid distributor (4) and the conduit with the pump (P _S) is (T _S) and are connected by branch conduit (T _4), also reservoir (S) And the liquid spreader (3) are connected by a pipe (T _S ) and a branch pipe (T ₃ ), and the liquid reservoir (S) and the liquid spreader (2) are connected by a pipe (T _S ) and It is connected by a branch line (T ₂ ).

That is, the heat transfer tube group and the last row heat transfer tube (A ₄ ) are connected in series by the absorption liquid pipeline so that the absorption liquid flows in series, and the frontmost row of the heat transfer tube group is also configured. The absorption liquid recirculation path is formed in the heat transfer tubes (A ₂ ) and (A ₃ ) excluding the heat transfer tube (A ₁ ).

Further, (F) is a fan for sucking in air, whereby outside air flows through the heat transfer tubes (A ₄ ), (A ₃ ), (A ₂ ), and (A ₁ ) in order. Note that (5), (5) ... Are fins provided on the outer wall of the heat transfer tube.

An air-cooled absorber having such a structure (hereinafter referred to as "this device")
In, for example, when a concentrated absorption liquid [lithium bromide aqueous solution] having a concentration of 60% flows into the liquid sprinkler (1) and is dripped on the peripheral portion of the horizontal portion of the heat transfer tube (A ₁ ), the dripped absorption liquid is A liquid film flows down along the inner wall surface of the vertical portion of the heat transfer tube (A ₁ ) while forming a liquid film, and the absorbing liquid absorbs the gaseous refrigerant in the tube (A ₁ ) and lowers its concentration. Then, the concentration of the absorbing liquid flowing down to the bottom of the heat transfer tube (A ₁ ) becomes about 59%, and the absorbing liquid of this concentration falls into the liquid reservoir (S). Part of the absorbing liquid that has dropped into the liquid reservoir ( _S ) is sent to the liquid spreader (4) of the heat transfer pipe (A ₄ ) by the pump (P _S ), while part of it is transferred to the heat transfer pipes (A ₃ ), (A _It is sent to the liquid sprayers (3) and (2) in 2). Then, about 59 drops were dropped from the liquid sprayer (4) on the peripheral edge of the horizontal portion of the heat transfer tube (A ₄ ).
The absorption liquid with a concentration of about 10% flows down at the bottom of the heat transfer tube (A ₄ ) while further reducing the concentration by flowing down as in the case of the heat transfer tube (A ₁ ).
Becomes 58% concentration, is returned to the generator [not shown] side by the pump (P _L). On the other hand, the liquid distributor (3), the heat transfer tubes from (2) (A _3), about 59%, which is dropped into the horizontal peripheral edge of (A ₂₎
Similarly, the absorption liquid having a concentration of about 5% becomes a concentration of about 58% at the bottom of these heat transfer tubes and drops again into the liquid reservoir (S). At this point, the absorption liquid in the liquid reservoir (S) has a concentration lower than 59%.
% Concentration.

Then, the absorbing liquid having a concentration of about 58.3% of the liquid reservoir (S) is recirculated to the heat transfer tubes (A ₃ ) and (A ₂ ) again, and the concentration is further lowered to drop into the liquid reservoir (S). The concentration of the absorption liquid in the liquid reservoir becomes even lower, by the way, it is about 57.8%.

The reflux of the absorbing liquid is repeatedly performed and the concentration of the absorbing liquid in the liquid reservoir (S) is lowered, so that the liquid is returned from the liquid reservoir to the generator side via the heat transfer tube (A ₄ ) in the last row. The concentration of the absorbent will eventually drop to nearly 56%. That is, in this device, the difference in concentration between the concentrated absorbing liquid and the dilute absorbing liquid is about 4%, which is similar to that of the shell-and-tube type water-cooled absorber.

Needless to say, the absorber of the present invention is not limited to the illustrated one. For example, the number of heat transfer tubes in the heat transfer tube group is set to four, and the concentrated absorbent liquid pipelines are connected to the liquid spreaders of the heat transfer tubes in the first and second rows while the third and fourth rows are connected. The heat transfer tubes or the heat transfer tubes in the second to fourth rows may be provided with an absorbing liquid return passage. Further, for example, the heat transfer tubes (A ₄ ) in the last row are arranged below the liquid reservoir (S) of the heat transfer tube group, and the liquid spreader (4) and the liquid reservoir (S) of this heat transfer tube are used as an absorbing liquid. You may make it connect in series with the flow-down pipe line. Furthermore, the heat transfer tubes connected in series with the heat transfer tube group are not limited to one heat transfer tube in the last row. That is, the heat transfer tubes connected in series with the heat transfer tube group may be two or more heat transfer tubes including the one in the last row, and these may be connected in series in order.

(G) Effect of the Invention As described above, according to the present invention, while cooling the outside of the heat transfer tube with a cooling medium such as air, the absorbing liquid flows down along the inner wall surface of the heat transfer tube to absorb the gaseous refrigerant in the tube. In the absorber of the configuration, the effect of improving its refrigerant absorption capacity to the same extent as a shell-and-tube type water-cooled absorber,
In other words, there is an effect that the refrigerant absorption capacity of the conventional air-cooled absorber can be enhanced.

Further, the present invention has a simple structure in which a part of the heat transfer tubes of the absorber is provided with an absorbing liquid return path, and is of practical value as a device capable of providing an air-cooled absorber having higher performance than the conventional one. It is expensive.

[Brief description of drawings]

The drawings are schematic structural explanatory views showing an embodiment of an air-cooled absorber according to the present invention. (A ₁ ) to (A ₄ ) ... Heat transfer tube, (1) to (4) …… Liquid sprayer, (D) …… Duct, (T _H ) …… Concentrated liquid conduit,
(S) ... Liquid reservoir, (T _S ) ... Pipe line, (P _S ) ... Pump,
(T ₂ )-(T ₄ ) …… Branching line, (T _L ) …… Line for dilute absorbing liquid.

Claims (2)

(57) [Claims] 1. A plurality of heat transfer tubes are arranged vertically or inclined, and while cooling the outside of these heat transfer tubes with a cooling medium, an absorbing liquid flows down along an inner wall surface of the pipe, and the absorbing liquid is vaporized in the inside of the pipe. In the absorber configured to absorb the refrigerant, all of the heat transfer tubes on the front row side except one or more heat transfer tubes including at least the heat transfer tubes in the last row are connected to a common liquid reservoir to form a heat transfer tube group, The heat transfer tube group and the other heat transfer tubes are respectively connected in series by an absorption liquid flow path to form an absorption liquid path for guiding the absorption liquid from the heat transfer tube group to the heat transfer tubes in the last row in series, and An absorber characterized in that the heat transfer tubes of the heat transfer tube group are provided with an absorption liquid recirculation path except at least that in the front row. 2. An absorber in which the cooling medium according to claim 1 is air.