JPH0225099Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an improvement of the evaporator/absorber of an absorption refrigerator.

Generally, the evaporator/absorber A of an absorption refrigerator includes an evaporator 1 consisting of a refrigerant liquid sparge device 1a and a heat transfer tube 1b, and an absorber 2 consisting of an absorption liquid sparge device 2a and a cooling water pipe 2b, as shown in Fig. 1. The refrigerant liquid 4 is disposed in the evaporation absorption cylinder 3 which is kept in a high vacuum state, and is evaporated onto the heat transfer tube 1b to cool the fluid 5 flowing through the heat transfer tube 1b, and is absorbed through the demister 6. The refrigerant vapor 4b that has migrated into the vessel 2 is absorbed by the absorption liquid 7 that has been spread from the absorption liquid distribution device 2a and has adhered to the cooling water pipe 2b.

Therefore, in order to efficiently perform the evaporation process of the refrigerant liquid 4 in the evaporator 1, it is necessary to
It is an essential requirement that the heat exchanger be uniformly dispersed onto the heat exchanger tube 1b. The same applies to the absorber 2, and in order to efficiently absorb refrigerant vapor, the absorbent liquid 7 must be uniformly spread over the cooling water pipe 2b, and an absorbent liquid film must be formed on the outer surface of the absorber 2. must be formed evenly.

On the other hand, as the refrigerant liquid distribution device 1a and the absorption liquid distribution device 2a, tray type distribution devices and spray type distribution devices have been widely used. That is,
In the former, the refrigerant liquid sent from the condenser and the concentrated absorption liquid sent from the regenerator are temporarily stored in the gutter, and the refrigerant liquid ( The latter uses a nozzle to spray refrigerant liquid (or absorption liquid) onto the heat transfer tubes (or cooling water tubes). .

However, heat transfer tubes (or cooling water tubes) as described above
With a sprayer that sprays refrigerant liquid (or concentrated absorption liquid) directly onto the top, the amount of liquid sprayed from multiple nozzles or siphon tubes tends to be uneven due to various reasons, and the amount of liquid sprayed from the heat transfer tube (or cooling water tube) tends to be uneven. Generally, it is quite difficult to uniformly disperse the refrigerant (or concentrated absorbent liquid) over the entire surface. On the other hand, even in spray-type evaporators and absorbers, a so-called carry-over occurs in which the refrigerant mist that is blown up when it hits the heat exchanger tubes moves to the absorber side together with the refrigerant vapor, or when there is a cooling problem near the nozzle. There is a problem in that the absorption liquid film on the water pipe is blown downward by the sprayed concentrated absorption liquid, making the thickness of the absorption liquid film too thin.

For example, in the conventional spray type evaporator 1 as shown in FIGS. 2 and 3, each adjacent nozzle 9, The amount of the refrigerant liquid 4 sprayed from the tube 9 is often uneven, and as a result, the wetting state of the outer surface of the heat transfer tube 1b with the refrigerant liquid becomes uneven, as shown in FIG. 3, and the heat transfer characteristics deteriorate. This will lead to a decrease in the performance of the evaporator.

Furthermore, as shown in FIG. 2, when the refrigerant liquid 4 sprayed at high speed from the nozzles 9, 9 directly collides onto the heat transfer tube 1b and becomes atomized, the ability of the demister 6 to supplement fine mist is reduced. Since this is not sufficient, the refrigerant splashes move toward the absorber 2 on the high-speed refrigerant vapor flow 4b flowing in the direction of the arrow, impeding the absorption performance of the absorber.

The present invention aims to solve the above-mentioned problems in the evaporator/absorber of an absorption refrigerator.
It is possible to spray the refrigerant liquid to the heat transfer tubes and the absorption liquid to the cooling water pipes extremely uniformly, prevent carryover of refrigerant splashes, and uniformize the thickness of the absorption liquid film on the outer surface of the cooling water pipes. The purpose of this invention is to provide an evaporator/absorber for an absorption chiller that enables this.

An evaporator 1 consisting of a refrigerant liquid header 8 provided with a nozzle 9 and heat transfer tubes 1b arranged in a lattice shape in a cross-sectional view below the refrigerant liquid header 8 in an evaporator absorption shell 3;
2 and an absorber 2 consisting of an absorber 2 comprising an absorber header 11 with a demister 6 and cooling water pipes 2b arranged below it in a lattice shape in cross-sectional view, with a demister 6 interposed therebetween. In the evaporator/absorber, the upper position between the adjacent heat exchanger tubes 1b, 1b of the horizontally arranged uppermost heat exchanger tube row and the adjacent cooling water tube row of the horizontally arranged uppermost cooling water tube row. A certain narrow G is maintained above each heat transfer tube 1b and each cooling water tube 2b in the upper position between the water tubes 2b, 2b, and a liquid having a circular, semicircular, inverted U-shaped, or inverted V-shaped cross section is parallel to this. The redistributor 10 is disposed, and between the uppermost heat exchanger tube 1b closest to the absorber 2 and the upper part of the demister 6, the heat exchanger tube 1b and a narrow
The basic structure of the invention is that G' is held and a baffle plate 13 is provided.

Furthermore, by adopting the above configuration, the refrigerant liquid is uniformly distributed to the heat transfer tubes, and the performance of the evaporator is greatly improved. At the same time, there is no so-called carry-over of the blown refrigerant, which reduces the performance deterioration of the absorber. can be prevented. In addition, the distribution of the absorption liquid is made even, and the thickness of the absorption liquid film itself is also made uniform.
The absorption performance of the absorber is greatly improved.

Hereinafter, the details will be explained based on an embodiment of the present invention shown in FIGS. 4 and 5. Note that the same reference numbers are used for the same parts as in FIGS. 1 to 3.

FIG. 4 is a sectional view showing the main parts of the evaporator/absorber according to the present invention, in which 8 is a refrigerant liquid header, 9 is a nozzle, 1b is a heat transfer tube, 11 is an absorption liquid header, and 12 is a nozzle. , 2b are cooling water pipes.
Moreover, 10 is a liquid redistribution body made of a pipe disposed above the heat exchanger tube 1b, and is located between the uppermost row of heat exchanger tubes, and has a slight narrow gap between it and each of the uppermost heat exchanger tubes. 〓G is provided and arranged parallel to each heat exchanger tube 1b, 1b. Furthermore, 13 is a baffle plate, and its base end is fixed to the demister support 14 with a slight gap G' between it and the heat exchanger tube 1b located at the uppermost position on the absorber side. .

The refrigerant liquid 4 sprayed from the nozzle 9 is first applied to the outer surface of the liquid redistributor 10 and the top row of heat exchanger tubes 1b.
colliding with the outer surface of the group, the heat exchanger tubes 1b in the second row and below
There is no direct collision with the group. Therefore, there is almost no splash of refrigerant liquid between the groups of heat transfer tubes 1b in the second row and below, and there is no carryover of the refrigerant splash due to the refrigerant vapor 4b as in the conventional evaporator.

On the other hand, as the refrigerant liquid 4 collides with the top row of heat transfer tubes and the liquid redistributor 10, refrigerant splash is generated in a part of the area where the redistributor 10 is disposed. However, in this region, the amount of refrigerant vapor 4b itself is small, and most of its flow velocity is lost by the sprayed refrigerant liquid, so there is almost no carryover of the so-called refrigerant vapor. do not have. Moreover, since the baffle plate 13 is provided, even if the splashed refrigerant were to scatter to the absorber 2 side, it would be returned to the heat transfer tubes and directly transferred to the absorber 2 side. Never.

The refrigerant 4a that collides with the heat exchanger tube 1b group in the uppermost row and the liquid redistributor 10 and becomes droplets is transferred to the liquid redistributor 10.
The refrigerant flows downward through the gap G between the heat exchanger tubes in the top row, passes along the outer surface of the heat transfer tubes 1b in the top row, and drips as large refrigerant droplets 4a onto the heat transfer tubes in the second row and below. Go. It should be noted that the droplets that have passed through the slit G along the outer surface of the liquid redistributor 10 drop downward due to gravity in front of the slit G or in the middle thereof, and pass through the heat transfer tubes in the top row. It will merge with the traveling droplets. Therefore, there are almost no droplets dripping in the space between the heat exchanger tubes 1b, 1b.

On the other hand, in the event that a difference occurs in the axial distribution of the amount of refrigerant droplets in the narrow gap G due to the difference in the amount of spray from each nozzle 9, 9, the liquid redistributor 10 and the heat transfer tube 1b and the refrigerant droplet 4
A part of the refrigerant droplet 4a flows in the axial direction while the refrigerant droplet 4a passes through the refrigerant droplet 4a. As a result, the axial distribution of the amount of refrigerant droplets passing through is adjusted, resulting in an extremely uniform dispersion state, and the nozzle 9 and refrigerant liquid header 8 (in the case of the tray method, the gutter and distribution siphon pipe, etc.)
The precision required for manufacturing and mounting will be significantly reduced. In the above embodiment, since a pipe is used for the liquid redistribution body 10, it is of course possible to pass the fluid 5 into the pipe and use it as a part of a heat transfer tube (evaporation tube). Moreover, the shape of the liquid redistributor 10 is not limited to a pipe-like shape, and the cross-sectional shape may be a semicircle, an inverted U-shape, or an inverted V-shape.

FIG. 5 shows a second embodiment of the present invention, in which a liquid redistributor 10 having a chevron-shaped cross section is used in both the evaporator 1 and the absorber 2. In this embodiment, since the liquid redistributor 10 is also provided on the absorber 2 side, there will be no difference in the spray amount from each nozzle 12, as in the case of the evaporator 1 of the first embodiment. Even if this occurs, the dispersed absorption liquid 7 will be dispersed and dripped onto the top row of cooling water tubes in an extremely uniform manner, and the refrigerant vapor absorption performance of the absorber 2 will be greatly improved.

As mentioned above, in this invention, a liquid redistribution body is provided above the heat transfer tubes of the evaporator and the cooling water tubes of the absorber with a certain gap G between them and the uppermost tube row. , the refrigerant or the refrigerant and the absorption liquid are automatically distributed uniformly, and the performance of the evaporator and absorber is greatly improved.

Furthermore, on the evaporator side, carryover of the blown refrigerant to the absorber side is almost completely prevented, making it possible to reduce the burden on the absorber.

As mentioned above, the present invention has excellent practical effects.

[Brief explanation of the drawing]

FIG. 1 is a schematic vertical cross-sectional view of a conventional evaporator/absorber A, FIG. 2 is a partial longitudinal cross-sectional view of a conventional spray-type evaporator, and FIG. 3 is a partial front view of FIG. FIG. 4 is a vertical cross-sectional view showing the main parts of the evaporator/absorber A according to the present invention, and FIG. 5 is a vertical cross-sectional view showing the main parts of another embodiment of the present invention. A... Evaporator/absorber, G... Slit, 1... Evaporator, 1a... Refrigerant liquid distribution device, 1b... Heat exchanger tube, 2
...Absorber, 2a...Absorption liquid distribution device, 2b...Cooling water pipe, 3...Evaporation absorption shell, 4...Refrigerant liquid, 5...
...Fluid, 6...Demister, 7...Absorption liquid, 8...
...Refrigerant liquid header, 9, 12... Nozzle, 10...
... Redistribution body, 11 ... Absorption liquid header, 13 ...
baffle board.

Claims (1)

[Scope of utility model registration request] An evaporator 1 consisting of a refrigerant liquid header 8 provided with a nozzle 9 and heat transfer tubes 1b arranged in a lattice shape in a cross-sectional view below the refrigerant liquid header 8 in an evaporator absorption shell 3;
An absorption refrigerating machine formed by disposing an absorber 2 consisting of an absorption liquid header 11 having an absorbent liquid header 2 and cooling water pipes 2b arranged in a lattice shape in a cross-sectional view below the absorber 2 with a demister 6 interposed therebetween. In the evaporator/absorber, the upper position between the adjacent heat exchanger tubes 1b, 1b of the horizontally arranged uppermost heat exchanger tube row and the adjacent cooling water tube row of the horizontally arranged uppermost cooling water tube row. At the upper position between the water tubes 2b, 2b, a certain narrow G is maintained with each heat transfer tube 1b and each cooling water tube 2b, and parallel to this, a cross-sectional shape of a circular, semicircular, inverted U-shape, or inverted V-shape is formed. While disposing the liquid redistribution body 10,
An absorption refrigerator characterized in that a baffle plate 13 is disposed between the uppermost heat exchanger tube 1b closest to the absorber 2 and above the demister 6, holding the heat exchanger tube 1b and the narrow diameter G'. Evaporator/absorber.