JPH0721366B2 - Absorber - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention allows a cooling medium such as air to flow outside a heat transfer tube while allowing an absorbing liquid to flow down along an inner wall surface of the heat transfer tube while allowing a gaseous state inside the tube to flow. The present invention relates to a type of absorber that absorbs a refrigerant.

(B) Conventional technology The above-mentioned type of absorber 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 expand 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 absorber of the above type which has been proposed to reduce these drawbacks, for example,
As seen in Japanese Patent Laid-Open No. 56-92063, a plurality of heat transfer tubes having a predetermined length are arranged in parallel, and each of these heat transfer tubes is sprayed with a concentrated absorbing liquid having a strong refrigerant absorbing power from the generator side. An air cooling system that absorbs the refrigerant while flowing the absorbing liquid along the wall surface, collects the rare absorbing liquid that has flowed down to the bottom of each of these heat transfer tubes in a liquid reservoir, and returns the collected rare absorbing liquid to the generator side again. There is a type absorber.

(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 absorption liquid is high and the degree of absorption of the refrigerant by the absorption liquid is small. For example, in a conventional air-cooled absorber, each heat transfer tube has a concentration of 60%.
5 ~ 6 ℃ from the evaporator by spraying the lithium bromide aqueous solution of
As a result of an experiment to absorb a certain amount of water vapor, the concentration of the lithium bromide aqueous solution flowing down into the liquid reservoir of the absorber is about 59%, and the difference in concentration between the concentrated absorbing liquid and the diluted absorbing liquid is about 1%. I understood. 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%. It was found that that of the conventional air-cooled absorber is about 1/4 to 1/3, which is far lower than the refrigerant absorption capacity of. 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 of the type described above to the same extent as that of the shell-and-tube type water-cooled absorber,
The purpose is to put an air-cooled absorber with a simple structure into practical use.

(D) Means for Solving Problems As a means for solving the above-mentioned problems, the present invention relates to absorbing liquid by connecting heat transfer tubes arranged in an absorber of the above-mentioned type in series with absorbing liquid pipelines. Is sequentially flowed from the heat transfer tube on the upstream side to that on the downstream side, while a cooling medium such as air is sequentially flowed from the heat transfer tube on the downstream side to that on the upstream side.

(E) Action In the absorber of the present invention, the refrigerant is absorbed by the absorbing liquid in each heat transfer pipe from the most upstream heat transfer pipe of the absorbing liquid to the most downstream heat transfer pipe thereof, and the concentration of each is 0 to 1%. Make a difference,
The total concentration difference, that is, the concentration difference between the dilute absorbent and the concentrated absorbent that enters and leaves the absorber, is about 3 to 4% or 4%.
There is an action to do the above. Also, since the downstream heat transfer tube through which the low-concentration absorption liquid flows down is cooled by a medium such as air having a lower temperature, the refrigerant absorption capacity of the absorption liquid in the downstream heat transfer tube and that on the upstream side. The effect of reducing the difference between the heat transfer tubes can be reduced, and the unevenness in the capacity of the absorber as a whole can be reduced by mitigating the variation in the refrigerant absorption capacity between the heat transfer tubes.

Due to this action, even in an air-cooled absorber using outside air having a temperature level higher than that of cooling water as a cooling medium of the absorber, for example, a refrigerant absorption capacity equal to or higher than that of a shell-and-tube type water-cooled absorber is exhibited. It becomes possible. Further, it is possible to provide an air-cooled absorber having a simple structure in which a plurality of heat transfer tubes are arranged in series.

(F) Embodiment FIG. 1 is a schematic structural explanatory view 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 disperser (1) and the generator (not shown) side are connected by a concentrated absorbing liquid pipe (T _H ), while the bottom of the heat transfer tube (A ₄ ) and the generator side are for rare absorbing liquid. absorbing liquid between the absorber and the generator are connected by a pump (P _L) with a conduit (T _L) is circulated. And
Heat transfer tube (A ₁ ) bottom and liquid spreader (2), Heat transfer tube (A ₂ ) bottom and liquid spreader (3), Heat transfer tube (A ₃ ) bottom and liquid spreader (4)
Each pump (P ₁₎ with a conduit (T _1), a pump (P ₂₎ with a conduit (T _2), is connected with a pump (P ₃₎ with a conduit (T _3). That is, the four heat transfer tubes are connected in series by the absorbing liquid path.

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.

In the absorber having such a structure (hereinafter referred to as "this device"), for example, a concentrated absorbing liquid having a concentration of 60% [lithium bromide aqueous solution]
When flowing into the liquid sprayer (1) and dripping on the periphery of the horizontal part of the heat transfer tube (A ₁ ), the absorbed liquid drops along the inner wall surface of the vertical part of the heat transfer tube (A ₁ ). While flowing down, the absorbing liquid absorbs the gaseous refrigerant in the pipe (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%. Next, when about 59% of the absorbing liquid is sent to the liquid sprayer (2) by the pump (P ₁ ) and is dropped on the peripheral edge of the horizontal portion of the heat transfer pipe (A ₂ ) from this, the absorbing liquid is transferred to the heat transfer pipe (A ₂ ). _{As in the case of 1} ), the concentration is lowered by flowing it down, and the concentration of the absorbing liquid that reaches the bottom of the heat transfer tube (A ₂ ) becomes about 58%.
Similarly, the concentration of the absorbing liquid reaching the bottom of the heat transfer tube (A ₃ ) is about 57%, and the concentration of the dilute absorbing liquid reaching the bottom of the heat transfer pipe (A ₄ ) is about 56%. As described above, in this device, the difference in concentration between the concentrated absorbent and the diluted absorbent is about 4%.

Further, in this device, for example, outside air of about 30 ° C. is supplied by the fan (F), and the heat transfer tubes (A ₄ ), (A ₃ ),
Since the cooling air for the absorbing liquid flows in the order of (A ₂ ) and (A ₁ ) and the temperature level of the absorbing liquid in the heat transfer tubes is lowered in this order, the saturated vapor pressure in each of the heat transfer tubes is almost the same. To be kept at a level. By the way, the saturated vapor pressure is about 7mmHg, the temperature of the cooling air that passed through the heat transfer tube (A ₄ ) is about 33 ℃, that of the cooling air that passed through the heat transfer tube (A ₃ ) is about 36 ℃, the heat transfer tube (A ₂ ) After passing through the heat transfer tube (A ₁ ), the temperature is about 39 ℃. In this way, in this device, all of the heat transfer tubes (A ₁ ), (A ₂ ), (A ₃ ), and (A ₄ ) are kept at a saturated vapor pressure of about 7 mmHg and have the same refrigerant absorption capacity. Therefore, the bias of the ability as an absorber is alleviated.

In this device, although not shown, when the cooling air is circulated from the back side of the paper surface of FIG. 1 toward the front side, the heat transfer tubes (A ₁ ), (A ₂ ), (A ₃ ), (A ₃ By increasing the length in the order of ₄ ), it is possible to make the concentration of the absorption liquid at the bottom approximately 59%, 58%, 57% and 56%, respectively. Of course, in this case, there is a limit to the length of the heat transfer tube (A ₄ ).

FIG. 2 is a schematic structural explanatory view showing another embodiment of the absorber according to the present invention, in which the same components as those of the embodiment of FIG. 1 are designated by the same reference numerals. . Second
In the figure, (E) is an evaporator, which is equipped with a heat transfer tube (A ₁ ),
(A ₂ ), (A ₃ ), (A ₄ ) and duct (D ₁ ),
(D ₂ ), (D ₃ ), (D ₄ ), and the heat transfer tubes were connected in series with the absorption liquid flow-down conduits (T ₁ ), (T ₂ ), (T ₃ ). An example is shown. Further, (W) is a flow path of a cooling medium such as air. Also in the embodiment shown in FIG. 2, it is possible to make the concentration difference of the absorbing liquid flowing in and out of each heat transfer tube approximately 1%, and as in the embodiment shown in FIG. It is possible to prevent the deviation of the capacity and make the concentration difference about 4%, and to exhibit the same capacity as the shell-and-tube type water-cooled absorber.

In the absorber of the present invention, the number of heat transfer tubes may be 5 or more so that the concentration difference between the concentrated absorbing solution and the rare absorbing solution is 4% or more.

As described above, the absorber of the present invention has a simple structure in which a plurality of heat transfer tubes are arranged in series in the absorbing liquid pipeline even when it is air-cooled, thereby providing a concentrated absorbing liquid and a rare absorbing liquid. Of the water-cooled absorber capable of achieving a concentration difference of 3 to 4%.

(G) Effect of the Invention As described above, according to the present invention, while the cooling medium such as air is flowed outside the heat transfer conduit, the absorbing liquid is flowed down along the inner wall surface of the heat transfer conduit while the cooling liquid inside In the type of absorber that absorbs gaseous refrigerant, the effect of improving its refrigerant absorption capacity to the same extent as, for example, a shell-and-tube type water-cooled absorber, in other words, the refrigerant absorption of a conventional air-cooled absorber of the above type The effect of increasing the capacity and the effect of alleviating the variation in the refrigerant absorption capacity by making the saturated vapor pressures of the absorbing liquids in the respective heat transfer pipes substantially equal are provided.

Further, the present invention has a simple structure in which heat transfer pipes are connected in series by a pipe for absorbing liquid, and has a high practical value as a device capable of providing an air-cooled absorber having higher performance than conventional ones. Is.

[Brief description of drawings]

FIG. 1 is a schematic structural explanatory view showing an embodiment of an air-cooled absorber according to the present invention, and FIG. 2 is a schematic structural explanatory view showing another embodiment of the absorber according to the present invention. (A ₁ ) to (A ₄ ) ... heat transfer tube, (1) to (4) ... liquid sprayer,
_{(D) ~ (D 4)} ... duct, (F) ... fan, (T ₁₎ ~
(T ₃ ) ... Pipe line, (W) ... Coolant flow passage.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Yuito Kobayashi, 2-18 Keihan Hon-dori, Moriguchi-shi, Osaka Sanyo Electric Co., Ltd. (56) References JP 62-202972 (JP, A)

Claims (2)

[Claims] 1. A heat transfer tube in which a plurality of heat transfer tubes are arranged vertically or inclined and an absorbing liquid flows down along inner wall surfaces of these heat transfer tubes and a cooling medium is circulated outside the heat transfer tubes. In the absorber configured to absorb the gaseous refrigerant in the passage into the absorption liquid, the bottom of the heat transmission pipe and the top of the heat transfer pipe in the next row are connected by the absorption liquid passage to the heat transfer pipe on the most upstream side. A flow path for guiding the absorption liquid to the series on the most downstream side is formed, and a flow path for guiding the cooling medium to the series on the most upstream side from the heat transfer tube on the most downstream side is formed. Absorber. 2. An absorber in which the cooling medium according to claim 1 is air.