JP3091071B2 - Heat exchangers and absorption air conditioners - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat exchanger and an absorption air conditioner.

[0002]

2. Description of the Related Art Hitherto, for example, heat exchanger tubes for heat exchangers have been proposed in various shapes depending on the application, such as boiling, evaporating, condensing and absorbing, in order to improve the performance of the heat exchanger. Among them, a falling liquid film type heat exchanger is widely used for an absorber such as an absorption air conditioner and an evaporator. For example, in an absorber, a number of heat transfer tubes are arranged horizontally or vertically in a closed container, and the absorbing solution is allowed to flow down on the heat transfer tubes,
Absorbing heat generated when the absorbing solution absorbs the refrigerant vapor generated from the evaporator connected to the closed container is eliminated by the cooling medium via the heat transfer tube.

[0003] Absorption is caused by the difference between the evaporation pressure in the evaporator and the saturated vapor pressure of the absorbing solution flowing down on the surface of the heat transfer tube.
As the pressure difference increases, the absorption capacity improves. Since the saturated vapor pressure of the absorbing solution is lower as the temperature of the solution is lower and the concentration is higher, in order to improve the absorbing capacity,
The high cooling capacity keeps the solution temperature low,
It is necessary to keep the concentration of the absorbing solution as high as possible. For example, fins are formed at equal pitches on the surface of the heat transfer tube in order to increase the heat transfer area for the purpose of improving heat transfer performance. Japanese Patent Application Laid-Open No. 1-148180 discloses a method for improving the heat transfer performance of this type. However, these heat transfer tubes have a high cost per capacity, and thus low cost smooth tubes are often used.

Japanese Patent Application Laid-Open No. Sho 59-71083 and Japanese Patent Application Laid-Open No. S61-61609 disclose heat transfer promoting technology for a single-phase flow heat medium instead of a liquid film heat medium flowing down on a heat transfer wall surface.
As disclosed in JP-A-6595, a smooth projection is provided on the electric heating wall surface on the side where the single-phase flow medium flows, so that the flow of the heat medium is disturbed so as not to cause separation vortex, and the flow accompanying the flow of the heat medium is caused. There are some that attempt to improve heat transfer performance while preventing an increase in pressure loss as much as possible. However, it is necessary to form these smooth projections. The depression formed on the opposite side of the heat transfer wall surface has no effect on improving the heat transfer performance of the other heat transfer medium.

[0005] A liquid-filled evaporator is also known as a heat exchanger with a phase change. In order to promote the boiling phenomenon, as disclosed in Japanese Patent Application Laid-Open No. Hei. By forming a cavity in the heat transfer surface and making the area of the opening at the heat transfer surface smaller than the transverse opening area in a cross section parallel to the heat transfer wall, bubble nuclei effective for promoting boiling Is easy to generate.

As a heat transfer wall for condensation, Japanese Patent Laid-Open No.
As disclosed in JP-A-129197, a plurality of depressions are provided on the surface of the heat transfer wall, and the depth of the depression is set so that a liquid film generated by condensation of vapor on the heat transfer wall can be drawn into the depression and held for a certain period of time. By increasing the depth, the thickness of the liquid film on the heat transfer walls other than the depressions is reduced, thereby improving the condensation heat transfer performance.

[0007]

In the above prior art, various types of finned heat transfer tubes have been proposed so far in order to reduce the size and the performance of the refrigerator. In the conventional heat transfer tubes, fins are arranged on the heat transfer tubes in order to increase the cooling capacity, the pitch of the fins is reduced, and the heat transfer area is improved. However, when these heat transfer tubes are used for a liquid film falling down type heat exchanger such as an absorber of an absorption air conditioner, the absorption phenomenon occurs only on the surface of the absorbing solution liquid film, and only the concentration at the surface part decreases, resulting in When trying to increase the cooling capacity by simply arranging many fins in the heat transfer tube, the solution accumulates between the fins and the thickness of the liquid film increases, resulting in resistance to heat and mass transfer during absorption, The absorption capacity has not increased as much as expected. In addition, when the liquid film flows down the heat transfer tube due to these fins, the spread of the liquid film in the axial direction of the heat transfer tube becomes worse, and the further down the heat transfer tube, the less uniform the liquid film becomes. As a result, a portion where the liquid film did not exist was generated. If there is no liquid film made of the absorbing solution on the heat transfer tube, the absorption phenomenon does not occur, and as a result, the fin formed for promoting the absorption phenomenon may not work effectively. As a result, the absorption capacity could not be increased as expected.

Japanese Patent Application Laid-Open No. 1-134180 discloses a heat transfer tube in which a plurality of grooves are formed parallel to the tube axis in order to improve the agitation of the liquid film. There are problems that the processing is complicated and that the heat transfer area is inadvertently reduced by providing grooves.

The method of improving the absorption capacity by arranging the fins on the heat transfer tube results in an increase in the cost and processing cost of the copper material required to construct the heat transfer tube.
However, there are problems such as a low performance improvement ratio.

Further, as disclosed in Japanese Patent Application Laid-Open No. 58-129197, a plurality of depressions are provided on the surface of the heat transfer wall, and the liquid film on the heat transfer wall is drawn into the depression and held for a certain period of time. If the thickness of the liquid film flowing down is large as in the case of a falling liquid film heat exchanger, the thickness of the liquid film formed in the depression becomes large. However, there is a problem that the heat transfer resistance cannot be improved due to heat transfer resistance.

An object of the present invention is to provide a heat exchanger having a structure capable of enhancing heat transfer performance or absorption performance, and, in a heat transfer wall having a projection on a wall surface, promoting agitation of a fluid on the wall surface to enhance absorption performance. An object of the present invention is to provide an absorption air conditioner.

[0012]

SUMMARY OF THE INVENTION The present invention has a first surface through which a first fluid flows and a second surface through which a second fluid flows. In a heat exchanger for exchanging heat between at least one of the first surface and the second surface, at least two depressions are formed, and a partition is formed between the depressions. Height from the shortest distance imaginary line of adjacent dents,
Disclosed is a heat exchanger characterized by being lower elsewhere.

Further, the present invention discloses a heat exchanger, wherein the first surface and the second surface form an inner surface and an outer surface of the heat transfer tube.

Further, the present invention provides an evaporator, an absorber, a regenerator,
An absorption air conditioner comprising a condenser and using an absorption solution and a refrigerant, wherein the heat exchanger is used as an absorber is disclosed.

Further, the present invention discloses an absorption cooling / heating machine characterized in that the absorbing solution is an aqueous solution of lithium bromide and a surfactant is added to the absorbing solution.

Further, according to the present invention, a heat transfer tube is provided in the absorber, and the flow rate of the absorbing solution flowing down the outer surface of the heat transfer tube is 0.25 kg / m · s per unit length of the heat transfer tube. To 0.7 kg / m · s.

[0017]

FIG. 1, FIG. 2 and FIG. 3 show an embodiment. 1 is a cross-sectional view of a heat transfer wall, FIG. 2 is a liquid film shape diagram of the heat transfer wall surface, and FIG. 3 is an external view of a heat transfer tube using the heat transfer wall of FIG.

In FIGS. 1, 2 and 3, a depression 20 is formed in the surface of the heat transfer wall 21 in order to reduce the thickness of the falling liquid film and at the same time increase the solution surface area. This depression 20
Is formed so that the depth (hd) is smaller than the recess diameter (Dd).

In order to facilitate processing, the surface of the heat transfer wall must be 2
If the plane is a three-dimensional plane, the depression 20 is a plurality of straight lines or curves, and if the heat transfer wall surface is a three-dimensional surface, for example, as shown in FIG. It is provided intermittently at constant or regularly varying intervals along a curve or a plurality of straight lines parallel or perpendicular to the tube axis.

The inner surface of the depression 20 has a surface having a smooth curvature, and the cross-sectional opening area of the depression 20 decreases in the depth direction. Preferably, a smooth projection 29 is formed on the surface opposite to the depression 20, that is, on the back surface. The depth of the depression 20 is made larger than the thickness (t) of the heat transfer wall 21. In addition, depression 2 on the wall
There is a smooth surface 21A without zero, and the area of the smooth surface is 50% or less of the total plane area when the depression 20 is not formed.

The depression 20 formed on the surface of the heat transfer wall performs the following operation. Generally, when a liquid and a solid come into contact with each other, a meniscus is formed due to the influence of interfacial tension. If one of the radius of curvature of the interface formed by the meniscus in the Young-Laplace equation is large, the cross-sectional shape of the interface can be approximated to an arc. Therefore, if the depth of the dent 20 is larger than the dent diameter (or a circle equivalent diameter if it is not a circle), the thickness of the liquid film 22 formed in the dent 20 increases, and the thermal resistance increases. In the example, by reducing the depth of the depression 20 with respect to the diameter of the depression, the depression 2
The thickness of the liquid film 22 formed in the inside is reduced, the heat resistance is reduced, and the heat exchange performance is improved.

The following operation is also performed. (1) When there is a substance transfer other than heat, such as an absorption phenomenon, in the liquid film 22, the permeation rate of this substance diffusion increases. (2) The spread of the liquid film in the axial direction of the heat transfer tube is not hindered, and there is an effect that the film thickness of the falling liquid film formed on the surface of the heat transfer wall is made uniform in the axial direction of the tube. (3) When an aqueous solution of lithium bromide is used as an absorbing solution, and a surfactant is added to the solution in an amount of several tens to several hundreds ppm, when the solution gets over from the above-mentioned dent to the next dent, it absorbs refrigerant vapor. As the surface tension increases, the well-cooled absorbing solution in the depression is pulled up. Thereby, the convection of the absorbing solution is activated and the heat / mass transfer performance can be improved.

FIG. 4 shows the effect of increasing the absorption capacity.
As shown in FIG. 8, heat transfer tubes (four types from D1 to D4) in which the shape of the recess 20 was changed and a conventional smooth tube without a recess were made for performance comparison. In these, the shape and the diameter of the depression 20 are changed so that the shape of the depression 20 is hemispherical and the area expansion rate of the heat transfer surface becomes substantially equal. FIG. 4 shows the performance measurement results. In the figure, the horizontal axis represents the liquid film flow rate (kg / ms),
The vertical axis represents the heat transfer coefficient (W / m ² K). As is clear from the figure, the one with the highest performance is improved by 40% or more as compared with the smooth tube. From this result, it was found that a great effect can be expected when the depth of the depression 20 is 1 mm.

Furthermore, the shape of the depression on the surface of the heat transfer wall is not limited to an arc. Similar effects can be obtained with the shapes shown in FIGS. FIG. 5 is a plan view of the embodiment, FIG. 6 is a cross-sectional view thereof, and the plane of the depression 20A is a circle having a circular cross section, FIG. 7 is a plan view of another embodiment, and FIG. 9 is a plan view of still another embodiment, FIG. 9 is a plan view of another embodiment, FIG. 10 is a cross-sectional view of the embodiment, and the plane of the depression 20C is a circle and the cross section is conical. FIG. 11 is still another embodiment. FIG. 12 is a cross-sectional view of FIG. 12, and the plane of the depression 20D is a circle having a quadrangular pyramid cross section. FIG. 13 is a plan view of another embodiment, and FIG. 15 is a plan view of still another embodiment, FIG. 16 is a plan view of another embodiment, FIG. 16 is a cross-sectional view of the embodiment, and the plane of the depression 20F is square and the cross section is a quadrangular pyramid. FIG. 18 is a plan view of the example, and FIG. 18 is a cross-sectional view thereof. If, 19 is further plan view of another embodiment, FIG. 20 is the depression in the cross section 20
The plane H is a circle, the cross section of which is an arc and further has a depression at the bottom. FIG. 21 is a plan view of still another embodiment, and FIG. FIG. 23 is a plan view of still another embodiment, and FIG. 24 is a cross-sectional view of the embodiment, which is formed only by protrusions 20J.
The effect of increasing the leakage of the liquid film is slightly inferior to that of the recessed shape. Further, the arrangement of the depressions 20 may be as shown in FIGS. In the case of the heat transfer tube having the depression 20 of the embodiment shown in FIG. 1 described above, the heat transfer coefficient inside the tube is also increased. At this time, in order to promote the turbulence of the fluid in the pipe, the depression 20 is not staggered or square as shown in FIGS.
When the size of the depression 20 is changed as shown in 6, even higher effects can be obtained. FIG. 27 is effective in improving the uniformity of the liquid film on the heat transfer tube surface in the tube axis direction. FIG. 28 has the effect of creating a spiral turbulence in the fluid flowing in the pipe, and can improve the performance in the pipe. Further, as shown in FIG. 29, the performance inside the tube can be further enhanced by weakening the regularity of the arrangement of the depressions. As the combination for improving the performance on the outside and inside of the tube, the embodiments shown in FIGS. 30 to 32 are also highly effective. In the case where the heat transfer tube 21 is used upright against gravity and a liquid film flows down inside the tube, the performance can be improved by providing the depression 30 inside the tube as shown in FIG.

The heat transfer tube constructed as described above is provided with a spraying device for spraying a heat exchange medium above or to the side thereof, and a liquid film is formed on the heat transfer tube surface while the heat exchange medium flows down by gravity. A heat exchanger for performing heat exchange can be configured. Further, the heat exchange medium flowing down the surface of the heat transfer tube is configured to perform heat exchange accompanied with mass transfer with the gas in contact with the liquid film surface simultaneously with the flow down. In the most special case, it can be adopted in the absorber shown in FIG. 37 (the configuration will be described later). In particular, when the absorbent is an aqueous solution of lithium bromide and an organic substance is added to the absorbent as a surfactant, the depth of the depression 20 is set to 0.6 mm to 2.0 mm. The flow rate per unit length of the heat transfer tube on the side where the absorbing solution flows down the surface of the heat transfer tube for the absorber is 0.7 kg / m. s to 0.25 kg / m. s.

Next, a manufacturing method for manufacturing the heat transfer tube of the above embodiment will be described with reference to FIGS. FIG. 34 shows the shape of the heat transfer tube 21 in the manufacturing process. In this manufacturing method, a flat plate or a plate 21A having a curvature, which has been subjected to indentation in advance, is formed into a tube, and the contacting portions are joined by high-frequency welding or the like so as to be processed into a heat transfer tube. When processing is performed by such a manufacturing method, when forming the depression 20, the back side of the depression 20 can be held by an instrument, and the formation state of the depression 20 can be improved, and at the same time, the heat transfer tube after processing can be obtained. 21 can be made uniform, and material costs can be minimized. Further, the processing device shown in FIG. 35 includes feed rollers 31 and 31, and a tube forming device 35. By changing the positions of the dent processing rollers 33 and 34, the surface on which the dent 20 is formed can be easily changed to the inner surface or the outer surface of the tube.
A heat transfer tube having 0 can be manufactured by the same device.

FIG. 36 shows the structure of an absorption air conditioner using the heat transfer tube of the present invention. In FIG. 36, the absorption air conditioner includes a high-temperature regenerator 1, a low-temperature regenerator 2, a condenser 3, an evaporator 4, an absorber 5, a cooling tower 6, an indoor air heat exchanger 7, a refrigerant circulation pump 8, a solution pump 9, and cold water. Pump 10, cold water circulation pump 11, flow control valve 16, flow control three-way valve 16,
It is composed of a chilled water amount control valve 17 and a pipe connecting them. The absorber 5 includes a heat transfer tube 21 and a solution spraying device 36 as shown in FIG.

The refrigerant vapor generated from the high-temperature regenerator 1 is sent from the absorber 5 via the absorbing solution pump 9 to the low-temperature regenerator 2.
The refrigerant exchanges heat with the absorption solution flowing into the condenser, condenses while evaporating the refrigerant vapor from the absorption solution, and flows into the condenser 3 as a liquid refrigerant. The refrigerant vapor evaporated in the low-temperature regenerator 2 exchanges heat with the cooling water flowing in the heat transfer tube in the condenser 3 and condenses and liquefies while heating the cooling water. The refrigerant generated here flows into the evaporator 4, exchanges heat with cold water sent from the cold water circulation pump 11 flowing in the heat transfer tube, evaporates while cooling the cold water, and moves to the absorber 5. On the other hand, the chilled water flows into the indoor air heat exchanger 7 while controlling the flow rate by a plurality of chilled water amount control valves 17 for changing the capacity of the indoor air heat exchanger 7, and exchanges heat with the air to cool the air. It is heated and returns to the cold water circulation pump 11.

The refrigerant vapor generated in the evaporator 4 is absorbed by the absorbing solution flowing down on the heat transfer tube 21 in the absorber 5, and the generated heat of absorption is removed by the cooling water flowing in the heat transfer tube 21. The absorbing solution that has flowed down in the absorber 5 is sent from the solution pump 9 to the high-temperature regenerator 1 via the flow control valve 12 and also to the low-temperature regenerator 2, and a part of the flow control valve 13
And is recirculated to the absorber 5 through The absorption solution sent from the absorber 5 is heated by the boiler 19 in the high-temperature regenerator 1 and partially flows into the low-temperature regenerator 2 as a refrigerant vapor, while the concentrated absorption solution returns from the low-temperature regenerator 2. It mixes with the absorbing solution and is sprayed down by the solution spraying device 36 of the absorber 5 while the flow rate is controlled by the flow rate adjusting valve 15 to flow down.

The cooling water cooled down the cooling tower 6 is sent to the condenser 3 through the absorber 5 by the cooling water pump 10, but is partially condensed by the three-way valve 16, bypassing the absorber 5. It is sent to the vessel 3 and returns to the cooling tower 6. At this time, according to the change of the refrigeration load,
By controlling the opening of the three-way flow control valve 16 and the rotation speed of the blower fan 18 of the cool link tower, the cooling amount is adjusted by changing the condition of the cooling water. The above is the refrigeration cycle flow.

In the above-described absorption cooling / heating machine, the refrigerant vapor evaporated from the evaporator 4 is absorbed by the absorption solution flowing down only by gravity on the absorption heat transfer tube 21 installed horizontally in the absorber 5. At that time, the absorption solution generates dilution heat and is diluted. Since the absorption solution has a higher concentration and a lower temperature has a higher absorption capacity, the absorption heat is removed by cooling water flowing in the heat transfer tube, and the absorption temperature is maintained by lowering the temperature of the solution.

Therefore, in order to improve the absorption capacity, the height is low and the pitch (P
It is necessary to make the shape d) large and to reduce the thickness of the liquid film 22. In addition, since the flow of the liquid film in the axial direction is not hindered on such a heat transfer tube surface, there is an effect of preventing the liquid film from disappearing on the tube surface, and as a result, the absorption capacity can be improved.

Although the above embodiment is an example in which the heat transfer wall has a depression, there is also an embodiment in which a projection is provided opposite to the depression.
FIG. 38 is a sectional view of an embodiment having such projections on the heat transfer wall. In FIG. 38, the wall surface of the heat transfer wall 21A has a plurality of protrusions 29 and a bottom 100 extending between the protrusions.
FIG. 39 is a sectional view of still another embodiment of the heat transfer wall of the present invention. In FIG. 39, of the first fluid and the second fluid to be mutually thermally converted via the heat transfer wall 21A, a first wall surface on which the first fluid flows, and a second wall surface on which the second fluid flows And at least one of the first wall surface and the second wall surface, for example, the second wall surface has a projection 29 on the wall surface and a bottom 100 extending between the projections.

FIG. 40 is a sectional view of still another embodiment of the heat transfer wall of the present invention. In FIG. 40, of the first fluid and the second fluid to be mutually heat-converted via the heat transfer wall 21, the first wall surface on which the first fluid flows, and the inner wall surface on which the second fluid flows At least one of the outer wall surface and the inner wall surface has, for example, the inner wall surface having a projection 29 on the wall surface and a bottom portion 100 extending between the projections.

Further, when the heat transfer wall itself is thin, the embodiment of the depression as shown in FIGS. 1 to 17 has a projection when viewed from the opposite surface. In particular, when the heat transfer tube (FIGS. 34 and 35) is formed by a heat transfer wall using a thin flat plate, a depression is formed outside the tube and a projection is formed inside the tube. An example of the protrusion from the inside of the tube in such a case is included in one of the present embodiments. In the case of such a heat transfer tube, the relationship between the depression pitch and the depression depth as in the above embodiment may or may not be satisfied.

FIGS. 41A and 41B show FIGS.
FIG. 42 is a schematic view of an embodiment of the shape of the bottom between protrusions along the imaginary line of the shortest distance in the front direction of the protrusion arrangement and the arrow perspective direction of FIG.
(A), (b) is a schematic view of another embodiment of the shape of the bottom between protrusions along the shortest distance imaginary line in the perspective direction of the arrow and the front surface of the protrusion arrangement of FIGS. 38 to 40, and FIG. (B) is a schematic view of still another embodiment of the shape of the bottom between protrusions along the shortest distance imaginary line in the perspective direction of the arrow and the front of the protrusion arrangement of FIGS. 38 to 40, and FIG. ), (B) and FIGS. 42 (a), (b) show the staggered arrangement of the protrusions 29 different from each other in the overall flow direction of the fluid flowing on the wall surface, and FIGS. 43 (a), (b) Are projection arrangements in which the projections 29 are squarely arranged with respect to the overall flow direction of the fluid flowing on the wall surface.

From FIGS. 41 (a) and (b) to FIG. 43 (a),
In any of the embodiments shown in (b), the outer shape line and the shortest distance imaginary line shown in FIGS. 41 (b) to 43 (b) are equal, and the wall surface of the heat transfer wall 21A shown in FIGS. From the inner wall surface of the heat tube 21, FIG.
(A), (b) The bottom 10 between the projections 29 on the wall surface along the shortest distance imaginary line passing through the shortest distance between the adjacent projections 29 (one projection and one or more projections closest to it).
0 has a continuously curved shape, and is an imaginary plane parallel to the overall flow direction of the fluid flowing thereon, that is, parallel to the wall surface of the heat transfer wall 21A and substantially parallel to the longitudinal axis direction of the heat transfer tube 21. (If the inner wall surface of the heat transfer tube 21 is roughly a cylindrical tube, the imaginary surface is cylindrical, and if the inner tube is almost a square tube, the imaginary surface does not extend along the prism.) The contact point extends in a direction away from the virtual surface from the one point and has no portion extending on the virtual surface. The tapered shape of the bottom 100 along the shortest distance imaginary line is such that the fluid flowing on the wall surface of the heat transfer wall 21A and the inner wall surface of the heat transfer tube 21 is
00 prevents flow in the same direction parallel to the wall surface of the heat transfer wall 21A and in a direction substantially parallel to the longitudinal axis direction of the heat transfer tube 21 and flows on the wall surface of the heat transfer wall 21A and the inner wall surface side of the heat transfer tube 21. The fluid is urged substantially perpendicular to the general flow direction of the fluid to promote agitation of the fluid on the wall. The shortest distance imaginary line may be a shortest distance imaginary surface depending on the shapes of the protrusion 21 and the bottom 100.

It should be noted that FIGS. 41 (a) and (b)
In the embodiments of (a) and (b), FIGS.
The distance between the first wall surface and the second wall surface and the distance between the outer wall surface and the inner wall surface of the heat transfer wall 21A and the heat transfer tube 21 at the tip of the projection are:
Bottom 100 along the shortest distance imaginary line between adjacent protrusions 29
May be made larger in some of them. In addition, the first
The distance between the wall and the second wall, and the distance between the outer wall and the inner wall,
At the tip of the projection, a bottom 1 away from the shortest imaginary line
Other portions of 00 may be smaller.

FIG. 44 is a schematic view of still another embodiment of the shape of the bottom between projections along the imaginary line of the shortest distance in the perspective direction of the projection arrangement of FIGS. 41 to 43. In FIG. 44, the protrusion 2 along the shortest distance virtual line between the adjacent protrusions 29 is shown.
The bottom 100 between 9 has a discontinuously curved shape. FIG. 45 is a schematic view of another embodiment of the shape of the bottom between projections, which is away from the shortest imaginary line in the Y perspective direction of the projection arrangement of FIG. 43. In Figure 45, the projections the shortest distance depth h ₁ of the protrusions between the bottom 100 along the imaginary line between the projections 29 adjacent the Figure 43 away from the shortest distance phantom line in FIG. 45 2
9 it is preferable smaller than the depth h ₂ between.

FIG. 46 is a schematic sectional view showing one embodiment of the shape of the depression along the wall opposite to the projection of the heat transfer wall in FIG. 45 from FIG. 39 and the shortest distance imaginary line of the partition wall (partition wall) therebetween. FIG. In FIG. 46, a plurality of dents 20 on the opposite side of the protrusion 29 and a partition wall 200 between the dents 20 adjacent to the dents 20 are provided, and the shortest distance virtual line between the adjacent dents 20 in the depth direction of the dents 20 is provided. the height h ₃ for some of the recess bottom of the partition wall (partition wall) 200 along may be lower than the height to the other part of the recess bottom of the outermost short imaginary line from a remote partition wall (partition wall) 200 .

FIG. 47 is a schematic front view of still another embodiment of the arrangement and shapes of the projections shown in FIGS. FIG.
38 to 40, the protrusion 29 in the one direction of the heat transfer wall 21A and the longitudinal direction of the heat transfer tube 21, that is, the flow direction in the tube.
May be longer than the length of the protrusion 29 in one direction of the heat transfer wall 21A and a direction orthogonal to the longitudinal direction of the heat transfer tube 21.

The heat transfer tube 21 shown in FIGS.
37 can be used as the heat exchanger in the absorber 5 of FIG. 37 and the absorption air conditioner of FIG.

[0043]

According to the present invention, since the liquid film of the liquid flowing down the heat transfer wall and the heat transfer tube in the form of a liquid film is thinned, the heat resistance of the liquid film at the time of heat exchange can be reduced. Improve the heat transfer performance of heat tubes. In addition, when there is a substance transfer other than heat, such as an absorption phenomenon, in the liquid film, the permeation rate of this substance diffusion can be increased, so that the absorption capacity is increased. Further promotes the stirring of the fluid in the heat transfer wall and heat transfer tube,
Promotes heat exchange. Due to such effects, the efficiency and performance of the heat exchanger and the absorption air conditioner using the heat transfer wall and the heat transfer tube can be improved.

[Brief description of the drawings]

FIG. 1 is a sectional view of an embodiment of a heat transfer wall of the present invention.

FIG. 2 is a diagram of a liquid film shape on a heat transfer wall surface according to the present invention.

FIG. 3 is an external view of a heat transfer tube according to an embodiment of the present invention.

FIG. 4 is a performance comparison diagram of the heat transfer tube and the smooth tube of the present invention.

FIG. 5 is a plan view of an embodiment of the heat transfer wall of the present invention.

FIG. 6 is a cross-sectional view of the embodiment of FIG.

FIG. 7 is a plan view of still another embodiment of the heat transfer wall of the present invention.

FIG. 8 is a sectional view of the embodiment of FIG. 7;

FIG. 9 is a plan view of another embodiment of the heat transfer wall of the present invention.

FIG. 10 is a sectional view of the embodiment of FIG. 9;

FIG. 11 is a plan view of still another embodiment of the heat transfer wall of the present invention.

FIG. 12 is a sectional view of the embodiment of FIG. 11;

FIG. 13 is a plan view of still another embodiment of the heat transfer wall of the present invention.

FIG. 14 is a cross-sectional view of the embodiment of FIG.

FIG. 15 is a plan view of still another embodiment of the heat transfer wall of the present invention.

FIG. 16 is a cross-sectional view of the embodiment of FIG.

FIG. 17 is a plan view of still another embodiment of the heat transfer wall of the present invention.

18 is a sectional view of the embodiment of FIG.

FIG. 19 is a plan view of still another embodiment of the heat transfer wall of the present invention.

FIG. 20 is a sectional view of the embodiment of FIG. 19;

FIG. 21 is a plan view of still another embodiment of the heat transfer wall of the present invention.

FIG. 22 is a sectional view of the embodiment of FIG. 21;

FIG. 23 is a plan view of still another embodiment of the heat transfer wall of the present invention.

FIG. 24 is a cross-sectional view of the embodiment of FIG.

FIG. 25 is an external view of another embodiment of the heat transfer tube of the present invention.

FIG. 26 is an external view of still another embodiment of the heat transfer tube of the present invention.

FIG. 27 is an external view of still another embodiment of the heat transfer tube of the present invention.

FIG. 28 is an external view of still another embodiment of the heat transfer tube of the present invention.

FIG. 29 is an external view of still another embodiment of the heat transfer tube of the present invention.

FIG. 30 is an external view of still another embodiment of the heat transfer tube of the present invention.

FIG. 31 is an external view of still another embodiment of the heat transfer tube of the present invention.

FIG. 32 is an external view of still another embodiment of the heat transfer tube of the present invention.

FIG. 33 is an external view of still another embodiment of the heat transfer tube of the present invention.

FIG. 34 is an explanatory diagram of the method for manufacturing a heat transfer tube of the present invention.

FIG. 35 is an explanatory diagram of the method for manufacturing a heat transfer tube of the present invention.

FIG. 36 is a configuration diagram of an absorption cooling / heating machine.

FIG. 37 is an external view of an absorber using the heat transfer tube of the present invention.

FIG. 38 is a sectional view of still another embodiment of the heat transfer wall of the present invention.

FIG. 39 is a sectional view of still another embodiment of the heat transfer wall of the present invention.

FIG. 40 is a sectional view of still another embodiment of the heat transfer tube of the present invention.

41 (a) and (b) are schematic diagrams showing one embodiment of the arrangement of the protrusions of the heat exchange means and the shape of the bottom between protrusions along the imaginary line of the shortest distance according to the present invention.

FIGS. 42 (a) and 42 (b) are schematic views showing another embodiment of the arrangement of the projections of the heat exchange means and the shape of the bottom between projections along the imaginary line of the shortest distance according to the present invention.

FIGS. 43 (a) and (b) are schematic views showing still another embodiment of the arrangement of the projections of the heat exchange means and the shape of the bottom between the projections along the imaginary line of the shortest distance according to the present invention.

FIG. 44 is a schematic view showing still another embodiment of the shape of the bottom between protrusions along the shortest distance virtual line according to the present invention.

FIG. 45 is a schematic view showing the shape of the bottom between protrusions separated from the shortest distance virtual line.

FIG. 46 is a schematic view showing a shape of a depression according to the present invention and a partition wall therebetween along a virtual line of the shortest distance.

FIG. 47 is a schematic view showing another embodiment of the protrusion arrangement and the protrusion shape of the heat exchange means according to the present invention.

FIG. 48 is an explanatory diagram of performance measurement results of a heat transfer tube having a different shape of a depression and a smooth tube without a depression.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 High temperature regenerator 2 Low temperature regenerator 3 Condenser 4 Evaporator 5 Absorber 6 Cooling tower 7 Indoor air conditioner 8 Refrigerant pump 9 Solution pump 10 Cooling water pump 11 Cold water circulation pump 12, 13, 14, 15 Flow control valve 16 Flow control Three-way valve 17 Cold water control valve 18 Blower fan 19 Boiler 20, 20A to 20I Depression 20J Projection 21 Heat transfer tube 21A Heat transfer wall 22 Liquid film 29 Projection 31 Feed roller 32 Flat plate 33 Depression processing roller 35 Tube forming device 36 Solution spraying device 100 Bottom 200 compartment wall

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Tomohisa Ouchi 502, Kandatecho, Tsuchiura-shi, Ibaraki Pref. Machinery Research Laboratory, Hitachi, Ltd. Inside the factory (72) Inventor Sakuro Tsukada 3550 Kida Yomachi, Tsuchiura-shi, Ibaraki Prefecture Inside the Tsuchiura factory of Hitachi Cable, Ltd. (56) References JP-A-64-46546 (JP, A) JP-A-53-17589 (JP) , A) (58) Field surveyed (Int. Cl. ⁷ , DB name) F28F 1/12 F28F 1/40 F28F 1/42 F25B 37/00

Claims (5)

(57) [Claims] 1. A heat exchanger having a first surface through which a first fluid flows and a second surface through which a second fluid flows, and exchanging heat between the first fluid and the second fluid. In at least one of the first surface and the second surface, at least two depressions, a partition portion is formed between the depressions,
A heat exchanger characterized in that the height of the partition from the bottom of the depression is lower on the imaginary line of the shortest distance between adjacent depressions than in other places. 2. The heat exchanger according to claim 1, wherein the first surface and the second surface form an inner surface and an outer surface of the heat transfer tube. 3. An absorption air conditioner comprising an evaporator, an absorber, a regenerator, and a condenser, wherein an absorption solution and a refrigerant are used.
An absorption air conditioner using the heat exchanger according to claim 1 as an absorber. 4. The absorption air conditioner according to claim 3, wherein the absorption solution is an aqueous solution of lithium bromide, and a surfactant is added to the absorption solution. 5. A heat transfer tube is provided in the absorber, and the flow rate of the absorbing solution flowing down the outer surface of the heat transfer tube is:
0.25 kg / m · s per unit length of heat transfer tube
The absorption cooler / heater according to claim 4, wherein the pressure is 7 kg / m · s.