JPH10325643A - Absorber of absorption refrigerator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an absorber having a high absorbability. SOLUTION: Inside an absorber of an absorption refrigerator, a plurality of refrigerating pipes 2 which extend in a horizontal direction are arranged. A plurality of planar heat transfer plates 1 are arranged in a spaced-apart manner in a vertical posture and in a horizontal direction. The plurality of refrigerating pipes 2 pass through these heat transfer plates 1 in a vertical direction. The pitch Pd of the heat transfer plates 1 is set to 3-15 mm. On the upper surface of each heat transfer plate 1, an absorbent liquid reservoir 10 having a V-shaped cross section and extends in a longitudinal direction along the upper surface of the heat transfer plate 1 is integrally formed. On the bottom of each absorbent liquid reservoir 10, at positions located above both surfaces of the heat transfer plate 1, a plurality of absorbent liquid flow-out apertures 11 are formed in two rows with an interval in a longitudinal direction of the heat transfer plates 1. These absorbent liquid flow-out apertures 11 have their outlets abutted with the surfaces of the heat transfer plates 1. Due to such a construction, with a plurality of absorbent liquid reservoirs 10 formed in each heat transfer plate 1, an absorbent liquid supply mechanism is constructed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an absorber for absorbing refrigerant vapor generated from an evaporator into an absorbing liquid in an absorption refrigerator.

[0002]

2. Description of the Related Art In a double effect absorption refrigerator,
As shown in FIG. 16, an eliminator is provided inside the closed drum (3).
(30) is installed, and the evaporator room (31) and the absorber room
(32) is formed, an evaporator (not shown) is installed in the evaporator chamber (31), and an absorber (50) is installed in the absorber chamber (32).
A pipe (62) extending to a high-temperature regenerator through a low-temperature heat exchanger and a high-temperature heat exchanger is connected to the bottom of the closed drum (3). 6) is attached.

[0003] The absorber (50) comprises an absorbent spraying mechanism (4) connected to the tip of a pipe (61) extending from the low-temperature heat exchanger, and a plurality of cooling water pipes (2) extending in the horizontal direction. Cooling water piping system. In the absorber (50), the absorbing liquid (aqueous lithium bromide solution) is sprayed from the absorbing liquid spraying mechanism (4) toward the cooling water pipe (2) as shown by a broken line. The absorbing liquid absorbs the refrigerant vapor generated from the evaporator in the process of falling, and the absorbing liquid whose temperature has increased due to the heat of condensation and the heat of mixing (absorbing heat) generated at this time flows into the cooling water pipe (2). Is cooled by the cooling water flowing through.

[0004]

In the conventional absorber (50), the absorbing liquid sprayed from the absorbing liquid spraying mechanism (4) is:
First, it falls on the outer peripheral surface of the uppermost cooling water pipe (2), flows downward along the outer peripheral surface in a droplet form, and then falls on the outer peripheral surface of the lower cooling water pipe (2). . In this way, the absorbing liquid is transmitted to the lower cooling water pipe (2) in the order of droplets. Therefore, not only does the absorbing liquid fall at a relatively high speed due to the action of gravity, but also the cooling water piping
In (2), the absorption area of the absorbing liquid that should not absorb the refrigerant vapor and does not sufficiently spread to the outer peripheral surface, and the wetting area on the pipe surface are small. As a result, sufficient absorption and heat exchange were not performed, and there was a problem that the absorption capacity of the absorber was low. Therefore, an object of the present invention is to provide an absorber capable of obtaining a higher absorption capacity than before.

[0005]

In the absorber of the absorption refrigerator according to the present invention, an absorption liquid supply mechanism is provided in a closed chamber to which the absorption liquid and the refrigerant vapor are to be supplied. At the lower position of the absorbing liquid supply mechanism, a cooling water piping system formed by connecting a plurality of cooling water pipings extending in a lateral direction to each other in series or in parallel is installed, and a plurality of heat transfer plates are spaced from each other. The plurality of cooling water pipes penetrate these heat transfer plates.

In the absorber of the absorption refrigerator, the cooling water is supplied into the cooling water pipe, and the surfaces of the heat transfer plate and the cooling water pipe are sufficiently cooled by the cooling water. The absorbing liquid is supplied from the absorbing liquid supply mechanism to the surface of the heat transfer plate, and then the absorbing liquid spreads on the surface of the heat transfer plate,
It flows down along the surface of the heat transfer plate and the outer peripheral surface of the cooling water pipe. In this process, the absorbing liquid contacts the refrigerant vapor passing between the heat transfer plates with a sufficient area to absorb the refrigerant vapor. or,
The absorbing liquid wets the surface of the heat transfer plate over a wide area in the process of flowing down the heat transfer plate surface. Of course, the absorbing liquid is decelerated by the flow resistance and flows on the surface of the heat transfer plate over a sufficient time. Therefore, sufficient heat exchange is performed with the heat transfer plate surface, and the absorbing liquid is effectively cooled. As described above, the absorbing liquid comes into contact with the refrigerant vapor over a large area to absorb the refrigerant vapor, and the heat generated thereby is effectively cooled by sufficient heat exchange, and as a result, a high absorption capacity is obtained.

[0007] Specifically, the plurality of heat transfer plates are 3 m
They are arranged at a pitch of m to 15 mm.

[0008] In the process of flowing down the heat transfer plate, the absorbing liquid comes into contact with the refrigerant vapor passing between the heat transfer plates and absorbs the refrigerant vapor. Here, as the pitch of the heat transfer plates becomes smaller, the absorbents flowing on the opposing surfaces of two adjacent heat transfer plates approach each other, and when the pitch is smaller than 3 mm, the absorbents join and flow down. Will do. As a result, the flow path of the refrigerant vapor is blocked by the absorbing liquid, the refrigerant vapor does not contact the absorbing liquid with a sufficient area, and the absorption capacity is greatly reduced. Also, as the pitch of the heat transfer plate increases,
The number of heat transfer plates arranged over the entire length of the cooling water pipe is reduced, and the absorption area of the absorption liquid to absorb the refrigerant vapor and the wetting area of the absorption liquid to the heat transfer plate (the surface of the heat transfer plate attached to the heat transfer plate) When the contact area of the absorbing liquid with the surface of the heat transfer plate; m ² ) becomes small and the pitch exceeds 15 mm, the absorption and heat exchange amounts which are much larger than those of the conventional absorber without the heat transfer plate cannot be obtained. Therefore, the fin pitch is desirably set in the range of 3 to 15 mm.

[0009] More specifically, it is formed in a corrugated shape waving along the vertical direction. In addition, according to the specific shape in which the heat transfer plate is subjected to surface processing in which irregularities appear along the vertical direction, the flow resistance when the absorbing liquid flows down is increased, and the heat transfer plate has a vertical flat plate shape. Since the flow rate is reduced as compared with the hot plate, and the absorption area of the absorbing liquid and the wetting area of the absorbing liquid are increased, a larger amount of absorption and heat exchange can be obtained.

In another specific configuration, each heat transfer plate includes:
A plurality of steam circulation holes are opened apart from the outer peripheral surface of each cooling water pipe. In this specific configuration, the refrigerant vapor supplied into the closed chamber generates a flow along the heat transfer plate, and also generates a flow penetrating the heat transfer plate through the steam flow hole.
Therefore, the refrigerant vapor flows evenly in the closed chamber without being obstructed by the heat transfer plate, and is sufficiently absorbed by the absorbing liquid. In this case, the arrangement pitch of the plurality of heat transfer plates is desirably set in a range of 2 to 14 mm.

[0011]

According to the absorber of the absorption refrigerator according to the present invention, as compared with the conventional absorber, the absorbing liquid comes into contact with the refrigerant vapor over a wider area to absorb the refrigerant vapor and generate the same. The generated heat is effectively cooled by sufficient heat exchange, so that the absorption capacity is dramatically improved.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to an absorber of a double-effect absorption refrigerator will be specifically described below with reference to the drawings. First Embodiment The absorber of this embodiment is installed in an absorber chamber (32) formed in a closed drum (3), similarly to the conventional one shown in FIG. As shown in FIGS. 1 to 3, in the absorber (5) of the present embodiment, a plurality of cooling water pipes (2) extending in the horizontal direction are arranged in the absorber chamber (32), for example, 22 mm in length and width. Are arranged at a pitch of Also, a plurality of flat heat transfer plates (1)
Are arranged in the horizontal direction in a vertical position at an interval from each other, and the plurality of cooling water pipes (2) are
(1) penetrates vertically. For example, a flat copper plate having a thickness Td of 0.5 mm is used as the heat transfer plate (1).
As the heat transfer plate (1), other well-known materials, for example, those made of aluminum or the like can be used.
The pitch Pd of the heat transfer plate (1) is set to 3 to 15 mm.

At the upper end surface of each heat transfer plate (1), an absorbing liquid tank having a V-shaped cross section extending along the longitudinal direction of the upper end surface of the heat transfer plate (1).
(10) is formed integrally with the heat transfer plate (1). At the bottom of each absorption liquid tank (10), at the position above both surfaces of the heat transfer plate (1),
A plurality of absorption liquid flow holes (11) are formed in two rows at intervals in the longitudinal direction of the heat transfer plate (1), and the outlets of the absorption liquid flow holes (11) are connected to the heat transfer plate (1). ) Is in contact with the surface. In this manner, a plurality of absorbing liquid tanks (1) formed for each heat transfer plate (1) are provided.
0) constitutes the absorbing liquid supply mechanism.

In the absorber (5) of the absorption refrigerator, cooling water is supplied into a cooling water pipe (2), and a heat transfer plate (1) is provided.
The temperature of the surface of the cooling water pipe (2) is sufficiently lowered by the cooling water in the cooling water pipe (2). The absorbing liquid is supplied from the pipe (61) shown in FIG. 16 to the plurality of absorbing liquid tanks (10) of this embodiment shown in FIG. The absorbing solution is stored in an absorbing solution tank.
After temporarily accumulating in (10), it flows out from the outlets of the plurality of absorption liquid flow holes (11). The absorbent flowing out from the outlet of each absorbent flow hole (11) is immediately transferred to the surface of the heat transfer plate (1) as shown by the dashed arrow, and spreads on the surface of the heat transfer plate (1) while spreading. Hot plate
It flows down along the surface of (1) and the outer peripheral surface of the cooling water pipe (2). Here, all the absorbing liquid flowing down from the absorbing liquid tank (10) travels on the surface of the heat transfer plate (1), and does not drop in the form of a droplet as in the related art. In the process of flowing down the surface of the heat transfer plate (1), the absorbing liquid comes into contact with a sufficient amount of refrigerant vapor passing between the heat transfer plates (1) to absorb the refrigerant vapor. In this process, the absorbing liquid wets the surface of the heat transfer plate (1) over a wide area. Of course, since the absorbing liquid is decelerated by the flow resistance, it flows over the surface of the heat transfer plate (1) from the upper end to the lower end with a sufficient time. Thereby, a large heat exchange amount is obtained. As described above, the absorbing liquid comes into contact with the refrigerant vapor over a large area to absorb the refrigerant vapor, and the heat generated thereby is effectively cooled by sufficient heat exchange. As a result, a high absorption capacity is obtained.

FIG. 4 shows the results of a calculation on the absorption capacity performed to verify the effect of the present invention. The horizontal axis is the pitch Pd of the heat transfer plate (1), and the vertical axis is the same. It shows the ratio (V1 / V2) of the volume V1 of the absorber (5) of the present invention having an absorption capacity to the volume V2 of the conventional absorber (50). It can be said that the smaller the volume ratio, the higher the absorption capacity of the absorber (5) of the present invention. As shown in FIG. 5, the thickness Td of the heat transfer plate (1) is 0.5 mm, the outer diameter Dt of the cooling water pipe (2) is 1/2 inch or 5/8 inch, and the cooling water pipe ( 2)
The thickness Tt is 0.6 mm, the flow velocity of the cooling water flowing through the cooling water pipe (2) is 11.7 m / s, and the pitch P of the heat transfer plate (1) is
The experiment was performed while changing d. The plot of black circles in FIG. 4 indicates the calculation result when the outer diameter Dt of the cooling water pipe (2) is 1/2 inch, and the plot of white circles indicates the calculation result when the outer diameter Dt is 5/8 inch.

As shown in the figure, when the outer diameter Dt of the cooling water pipe (2) is 1/2 inch and when it is 5/8 inch, the heat transfer plate is used.
When the pitch Pd in (1) is 3 mm, the volume ratio is a minimum value of about 30%. Also, the pitch Pd of the heat transfer plate (1)
Increases from 3 mm, the volume ratio gradually increases. When the pitch Pd is 15 mm, the volume ratio is about 95% when the outer diameter Dt of the cooling water pipe (2) is 1/2 inch, and is about 80% when the outer diameter Dt is 5/8 inch. This is because as the pitch Pd of the heat transfer plates (1) increases, the number of heat transfer plates (1) arranged over the entire length of the cooling water pipe (2) decreases, and the absorption area of the absorbing liquid and Heat transfer plate
This is because the wetting area (m ² ) of the absorbing solution with respect to (1) becomes small. When the pitch Pd exceeds 15 mm, the wetted area is almost the same as that of the conventional absorber 50 without the heat transfer plate 1, and a heat exchange amount that is much larger than the conventional heat exchange amount cannot be obtained.

When the pitch Pd of the heat transfer plate (1) is smaller than 3 mm, the volume ratio is considered to increase rapidly as shown in FIG. This is because, when the heat transfer plates (1) approach each other, the absorbing liquids flowing on the two surfaces facing each other come into contact with each other, and these absorbing liquids merge and flow down. This is because the refrigerant vapor does not come into contact with the absorbing liquid in a sufficient area, and the absorbing capacity is greatly reduced. Therefore, the pitch Pd of the heat transfer plate (1)
Is desirably set in the range of 3 to 15 mm. As is clear from the graph of FIG. 4, according to the absorber (5) of the present embodiment, a higher absorption capacity can be obtained as compared with the conventional absorber (50). Since the required volume is small, the absorber (5) can be downsized.

Second Embodiment In the absorber (7) of this embodiment, a plurality of absorbing liquid tanks (10) integrally formed on the upper end surface of each heat transfer plate (1) constitute an absorbing liquid supply mechanism. The absorber (5) of the first embodiment is provided with a single absorbing liquid tank (8) attached across the upper ends of all the heat transfer plates (1) as an absorbing liquid supply mechanism. Specifically, as shown in FIGS. 6 to 8, a dish-shaped absorbing liquid tank (8) is attached across the upper end portions of all the heat transfer plates (1),
The upper ends of all the heat transfer plates (1) penetrate the bottom surface of the absorbing liquid tank (8). On the bottom surface of the absorbing liquid tank (8), slit-shaped absorbing liquid flow holes (81) (81) extending along the surface of the heat transfer plate (1) are opened on both sides of each heat transfer plate (1). I have. In this way,
As an absorbing liquid supply mechanism, an absorbing liquid tank (8) extending over the upper end portions of all the heat transfer plates (1) is attached.

In the absorber (7) of the absorption refrigerator, as in the first embodiment, the surfaces of the heat transfer plate (1) and the cooling water pipe (2) are inside the cooling water pipe (2). The temperature is sufficiently lowered by the cooling water. From the pipe (61) shown in FIG.
The absorbing liquid is supplied into the plurality of absorbing liquid tanks (8) of the present embodiment shown in FIG. The absorption liquid once accumulates in the absorption liquid tank (8), and then flows out from each absorption liquid flow down hole (81) along the surface of the heat transfer plate (1). At this time, since the absorbing liquid flows out in a thin film form from the slit-shaped absorbing liquid flow-down hole (81), the absorbing liquid flows down while wetting the entire surface of the surface of the heat transfer plate (1) in the width direction. Therefore,
The absorption area of the absorbing liquid and the wetting area on the surface of the heat transfer plate (1) are further increased as compared with the first embodiment. As a result, a higher absorption capacity can be obtained than in the first embodiment.

Third Embodiment As shown in FIG. 13, an absorber (70) of the present embodiment has a plurality of steam flow holes (12) formed in each heat transfer plate (1) of the first embodiment. is there. The cooling water pipes (2) have an outer diameter of 15.9 mm and a length of 2070 mm, are arranged in 17 rows × 18 stages, and have a total of 306 pipes. On the other hand, the heat transfer plate (1) is 396 mm
It has dimensions of × 374 mm × 0.5 t, and 345 sheets are arranged at a pitch of 6 mm. The steam flow hole (12) is shown in FIG.
As shown in FIG. 4, it has a diameter of 10 mm and is opened at the same pitch of 22 mm as the cooling water pipe through-hole (13).

In the first and second embodiments, the absorbing liquid supplied from the absorbing liquid tank (10) flows down while wetting the surface of the heat transfer plate (1). In (1), the above effect is exhibited in the surface area where the absorbing liquid spreads and is wet, but the other surface area where the absorbing liquid is not wet does not sufficiently exhibit the above effect. Therefore, in this embodiment, the heat transfer plate
Paying attention to the fact that a non-wetting surface area occurs in (1), the heat transfer plate
A plurality of steam circulation holes (12) are opened in (1) to generate a flow of refrigerant vapor passing through the heat transfer plate (1). by this,
The refrigerant vapor flows evenly in the absorber chamber (32) without being obstructed by the heat transfer plate (1), and is sufficiently absorbed by the absorbing liquid. In addition, by opening of steam circulation hole (12),
Since the steam flow is promoted, the arrangement pitch of the heat transfer plates (1) can be set smaller than in the case of the first embodiment and the second embodiment, thereby further improving the absorption capacity. I can do it.

For each of the absorber A of the present embodiment and the conventional absorber B without a heat transfer plate, small experimental machines having the same volume were produced, and the relationship between the flow rate of the absorbing solution and the refrigerating capacity was determined using this. As a result, as shown in FIG. 15, a relationship indicated by a broken line was obtained for the absorber A of the present embodiment, and a relationship indicated by a solid line was obtained for the conventional absorber B. The results in FIG. 15 are obtained by calculating the refrigerating capacity and the flow rate of the absorbing solution of the absorbers A and B having the above-described specifications based on the refrigerating capacity and the absorbing solution flow rate obtained by the experimental machine. As is clear from FIG. 15, the steam flow holes (1
Absorber A of this embodiment equipped with a heat transfer plate (1) in which 2) has been established
According to the above, regardless of the flow rate of the absorbing solution, a larger refrigerating capacity than the conventional absorber B can be obtained.

The configuration of each part of the present invention is not limited to the above embodiment, and various modifications can be made within the technical scope described in the claims. For example, a plurality of cooling water pipes (2)
Can be arranged in a staggered pattern as shown in FIG.

In place of the flat heat transfer plate (1), FIG.
Corrugated heat transfer plate (9) waving along the vertical direction as shown in (9)
It is also possible to employ. Also, FIGS. 11 (a) to 11 (c)
It is also possible to employ a heat transfer plate (90) that has been subjected to surface processing in which irregularities appear along the vertical direction as shown in FIG. When these heat transfer plates (9) and (90) are adopted, the flow resistance when the absorbing liquid flows down becomes large, and the heat transfer plate (1) having a vertical flat plate shape is obtained.
As compared with the above, the flow rate is reduced, and the absorption area of the absorbing liquid and the wetting area of the absorbing liquid are increased, so that a higher absorbing capacity can be obtained.

Further, as shown in FIG. 12, a plurality of semicircular absorbing liquid flow holes (81) are provided at the bottom of the absorbing liquid tank (8) shown in FIG. 82) can also be formed. Furthermore, the steam flow holes (12) shown in FIG.
Is not limited to a circular shape, but may be formed, for example, in a vertically long slit shape.

[Brief description of the drawings]

FIG. 1 is a partially cutaway perspective view showing a main part of an absorber according to a first embodiment.

FIG. 2 is a front view showing an arrangement of cooling water pipes in the absorber.

FIG. 3 is a side view showing an arrangement of heat transfer plates in the absorber.

FIG. 4 is a graph showing the results of calculations on absorption capacity performed to demonstrate the effects of the present invention.

FIG. 5 is a cross-sectional view illustrating shapes of a heat transfer plate and a cooling water pipe used in the above calculation.

FIG. 6 is a partially cutaway perspective view illustrating a main part of an absorber according to a second embodiment.

FIG. 7 is a front view showing an arrangement of cooling water pipes in the absorber.

FIG. 8 is a side view showing an arrangement state of heat transfer plates in the absorber.

FIG. 9 is a front view showing another arrangement state of the cooling water pipe.

FIG. 10 is a side view showing another shape of the heat transfer plate.

FIG. 11 is a cross-sectional view illustrating various cross-sectional shapes of the heat transfer plate.

FIG. 12 is a partially cutaway perspective view showing another example of the configuration of the absorption liquid flow-down hole in the absorber of the second embodiment.

FIG. 13 is a partially cutaway perspective view showing a main part of an absorber according to a third embodiment.

FIG. 14 is a diagram illustrating dimensions and pitches of a steam flow hole and a cooling water pipe through hole formed in a heat transfer plate.

FIG. 15 is a graph showing the relationship between the absorption liquid flow rate and the refrigeration capacity.

FIG. 16 is a schematic diagram showing an absorber installed in a closed drum in a double-effect absorption refrigerator.

[Explanation of symbols]

 (1) Heat transfer plate (10) Absorbent tank (11) Absorbent downflow hole (12) Steam circulation hole (2) Cooling water pipe (5) Absorber

Continuation of the front page (72) Inventor Kenji Nasako 2-5-5 Keihanhondori, Moriguchi-shi, Osaka Sanyo Electric Co., Ltd.

Claims (6)

[Claims] In an absorber of an absorption refrigerator, an absorption liquid supply mechanism is provided in a closed chamber to which the absorption liquid and the refrigerant vapor are to be supplied, and extends horizontally in a position below the absorption liquid supply mechanism. A cooling water piping system is installed by connecting a plurality of cooling water pipings in series or in parallel to each other, and a plurality of heat transfer plates are arranged in a horizontal direction in a vertical posture at intervals from each other. An absorber of an absorption refrigerator in which cooling water pipes penetrate these heat transfer plates. 2. The heat transfer plate according to claim 1, wherein the plurality of heat transfer plates have a thickness of 3 mm to 15 mm.
The absorber of the absorption refrigerator according to claim 1, wherein the absorber is arranged at a pitch of mm. 3. The absorber of an absorption refrigerator according to claim 1, wherein each heat transfer plate is formed in a corrugated shape waving along a vertical direction. 4. A heat treatment plate according to claim 1, wherein each heat transfer plate is subjected to surface processing in which irregularities appear along a vertical direction.
The absorber of the absorption refrigerator according to any one of the above. 5. A plurality of steam flow holes are formed in each heat transfer plate apart from an outer peripheral surface of each cooling water pipe.
The absorber of the absorption refrigerator described in 1. 6. The heat transfer plate according to claim 1, wherein the plurality of heat transfer plates are from 2 mm to 14 mm.
The absorber of the absorption refrigerator according to claim 5, which is arranged at a pitch of mm.