JPS63259386A - Cylindrical open rack type evaporator - Google Patents

Abstract

PURPOSE:To solve various problems caused by water sprinkling and lengthen the service life of a panel by disposing a sprinkler for sprinkling heating medium in the upper part of a heat exchanger which has vertically arranged finned tubes in a cylindrical form and annular header tanks at the top and the bottom. CONSTITUTION:The heat exchanging section 1 has multiple finned tubes 2 having fins 3 protruding in the form of a cross. The fins are mutally connected to form a cylinder comprising many tubes 2, and annular header tanks 4, 5 are disposed at the top and the bottom of the tubes 2 to allow the communication between them. Sprinklers 6, 7 for sprinkling heating medium are disposed in the upper part of the heat exchanging section 1 to uniformly sprinkle water both inside and outside the tubes 2 from above. This way, water is uniformly sprinkled to the finned tubes 2, and various problems caused by water sprinkling to the heat exchanging section can be solved. Further, the bowing phenomenon that can happen to the lower header tank can be prevented to lengthen the service life of a panel.

Description

[Detailed Description of the Invention] Field of Application The present invention relates to an open rack type evaporator for vaporizing liquefied natural gas, which improves the accuracy of sprinkling heat medium onto heat exchange tubes, and improves the accuracy of sprinkling heat medium onto heat exchange tubes. The present invention relates to an open rack type evaporator having a cylindrical shape or the like, which can eliminate the bowing phenomenon caused by a temperature difference on the lower surface, thereby achieving stability during steady operation and extending the life of the heat exchange section.

BACKGROUND ART Conventionally, an open rack type evaporator has been constructed by, for example, arranging a fin tube with a pair of fins protruding in the diametrical direction to form a single panel shape, and providing a header tank at the upper and lower ends of the fin tube. Constructing a heat exchange panel, a plurality of these panels are arranged in parallel, and seawater as a heat medium is allowed to overflow and flow down onto the heat exchange panel surface from a water sprinkler consisting of a water storage trough arranged above the bidirectional surface of each panel in the longitudinal direction. It is a structure.

During operation of such a panel-shaped open rack type evaporator, the water sprinkler troughs arranged in the longitudinal direction of both main surfaces of the heat exchange panel are structured so that water is supplied from two places, so that uneven flow of seawater is likely to occur. If the seawater in the trough drifts, the amount of seawater sprayed may be insufficient, or a partial supercooled area may occur in the heat exchange panel, causing abnormal swimsuits.

If a local temperature unevenness occurs in the heat exchanger panel as described above, there will be a local stress concentration on the fin tube, which may damage the heat exchange panel and require the operation to be stopped. However, various problems have arisen in terms of operation and durability of the equipment.

In addition, in conventional evaporation equipment, during operation, the heat medium such as seawater that is sprinkled is scattered on the rising periphery of the horizontally arranged lower header tank, resulting in less heat medium flowing down to the working periphery. Due to the temperature difference in the vertical direction of the lower header tank, a so-called bowing phenomenon occurs in which the lower header tank deforms into a bow, and the lower part of the fin tube, especially,
There was a problem in that the stress at the welded part with the header tank increased due to the change in shape, shortening the life of the panel.

Conventionally, for the purpose of preventing this bowing phenomenon, heat insulation (techniques such as attaching heat shields to the lower header tank to limit heat input from the outside) (Special Publication No. 34758) has been proposed, but the bowing phenomenon Furthermore, the above-mentioned heat-insulating structure may cause problems such as corrosion of structural materials by seawater.

In addition, in order to prevent the heat transfer water from colliding and scattering at the top of the lower header tank during watering, a side plate for water storage is placed at the bottom of the heat exchange panel, and water is stored between the panel and the side plate and dropped. An evaporator with a structure that alleviates the impact of water has been proposed (Japanese Utility Model Publication No. 58-22477), but the effect of improving the supply of heat transfer water to the bottom of the lower header tank is insufficient, and the upper part due to water storage There was a problem in that uniform heating could not be achieved due to temperature difference caused by heating only.

In this way, open rack type evaporators using conventional heat exchange panels have various problems due to their water sprinklers and the degree of water sprinkling. There is a strong need for an open rack type evaporator having a structure that can be implemented satisfactorily and that can prevent various stresses from being applied to the lower header tank.

Purpose of the Invention In view of the above-mentioned current situation, the present invention solves various problems associated with water sprinkling on the heat exchanger, prevents the bowing phenomenon that occurs in the lower header tank, and extends the life of the panel. The aim is to create an open rack type evaporator with a new shape and configuration that is simple in structure and easy to install.

Structure and Effects of the Invention The present invention arranges fin tubes in a row in a cylindrical shape,
A cylindrical tube characterized in that an annular header tank is provided at the upper and lower ends to constitute a heat exchange section, and a water sprinkler for discharging a heat medium for evaporating the liquefied gas in the tube is disposed above the heat exchange section. This is an open rack type evaporator.

Specifically, the cylindrical open rack type evaporator according to the present invention has a large number of fin tubes that are arranged in contact with each other or at predetermined intervals, for example, in a cylindrical shape, or similarly arranged in an arc shape. Multiple sets are arranged in a cylindrical shape, and annular header tanks are provided at the upper and lower ends of each fin tube, and they are communicated with each other to form a heat exchange section, and the liquefied gas is introduced into each tube from the lower header tank. The structure includes a water discharger disposed above the heat exchanger for sprinkling a heat medium to evaporate water.

In this invention, the heat exchange section is constructed by arranging fin tubes in a cylindrical shape and providing annular header tanks at the upper and lower ends of the heat exchange section. It can be made into a cylindrical shape or various rectangular cylindrical shapes,
Similarly, the annular header tank for supplying and collecting fluid can be circular, oval, rectangular, etc.

For example, by arranging the fin ube in a cylindrical shape and configuring it as a heat exchanger with annular header tanks arranged at the upper and lower ends, ■The trough of the water discharger can be arranged circumferentially, and uneven flow of seawater can be prevented. It is possible to improve the accuracy of watering the heat medium to the heat exchange tube, and it is possible to improve stability during steady operation.

■Since the header tank is annular, it is possible to eliminate the bowing phenomenon caused by temperature differences between the upper and lower surfaces of the lower header tank.

■Furthermore, since the lower header tank is annular, the HFS raw stress on the fin tube due to heat contraction of the rotating part is reduced, which eliminates the hoin phenomenon of the lower header tank and extends the life of the heat exchange part. be able to.

There are advantages such as

Disclosure based on drawings of the invention The present invention will be explained in detail below based on examples.

FIG. 1 is a perspective explanatory view of a heat exchange section of a cylindrical open rack type evaporator according to the present invention, and FIGS. 2A and 2B are longitudinal and cross-sectional explanatory views of the exchange section. Figure 3 a, b
The figure is a longitudinal cross-sectional view showing the configuration of a water sprinkler of a cylindrical open rack type evaporator according to the present invention. FIG. 4 is a perspective explanatory view showing an example of a combination of open rack type evaporators according to the present invention.

The heat exchange section (1) of the open rack type evaporator according to the present invention shown in FIGS. 1 and 2 has fins (3
) is constructed by using a large number of fin tubes (2) with projecting fins (2), and the fin tubes (2) are arranged in a cylindrical shape with the diametrical fins (3) in contact with each other. ,
Annular header tanks (4×5) are provided at the upper and lower ends of each of the arranged fin tubes (2), and are communicated with each other to form a heat exchange section.

A water sprinkler (6 x 7) for discharging a heat medium to the heat exchange section (1) having the above configuration is arranged above the heat exchanger to form a cylindrical open rack type evaporator according to the present invention. As such a water sprinkler, any type of water sprinkler, such as an overflow type or a water discharge type, can be used as long as it can uniformly spray water from the upper side to the lower side of each fin tube (2) arranged in a cylindrical shape. It can be applied even if

For example, the water sprinkler (6) shown in FIG. 3a has an annular trough (6a) arranged in layers facing the outer circumferential side of the upper end of the fin tube (2) of the heat exchange section (1) shown in FIG. , a circular trough (6b) arranged to fit into the inner diameter part of the cylindrical heat exchange part (1), and the side facing the fin tube (2), that is, the inner periphery of the annular trough (6a). The upper end of the side and the outer circumferential side of the circular trough (6b) is used as an overflow edge, and the seawater introduced into the trough overflows from the space between the troughs and the fin tubes (2) of the heat exchange section (1).
) consisting of a flowing configuration along the outer surface.

namely, an annular trough (6a) and a circular trough (6b)
Both have a simple circular shape, making it difficult for introduced seawater to drift and providing excellent watering accuracy.

Furthermore, the water sprinkler (7) shown in FIG. 3 is constructed by providing, for example, a portion in which no fin tube is arranged in a certain diameter direction in the heat exchange portion (1) shown in FIG. 1, that is, a substantially semicircular It is combined with a heat exchange part (1a) formed by two groups of fin tubes arranged in a cylindrical shape, and the water sprinkler (7) is made of a rectangular pallet-shaped container. , a symmetrical approximately semicircular groove (
7a) is provided, and the fin tube (
2), the lower part of the upper header tank (5) and the upper end of the fin tube (2) are immersed in the water sprinkler (7), and the seawater introduced into this container flows into the groove part (7a). ) and flows down along the outer surface of the fin tube (2).

That is, since the container shape of the water sprinkler (7) is simple and water is sprayed from the circular groove provided in the center of the bottom, it is difficult for seawater to drift in the container, and the water spray accuracy is excellent.

Therefore, in the evaporator according to the present invention having such a configuration, the liquefied gas introduced from the lower header tank (4) of the heat exchange section (1) is combined with the heat medium seawater flowing down along the outer surface of the fin tube (2). It rises inside the fin tube (2) while exchanging heat and evaporating, and eventually completely vaporizes.
It is collected in the upper header tank (5), from where it is led out through a connected manifold (9) to a gas storage tank.

The open rack type evaporator according to the present invention shown in FIG. 4 combines three sets of the heat exchange section (1a) and the water sprinkler (7) explained in FIG. 3 to form one unit. The upper and lower header tanks (4x5) of each heat exchanger (1a) are connected to a common manifold (8x9).

By adopting such a unit configuration, in particular, since one unit uses a plurality of cylindrical heat exchange parts (1) and one water sprinkler (10) common to these, it is possible to have a temporary panel heat exchange part. For use with water sprinklers on both sides of shiso.

Compared to conventional evaporation equipment that uses a trough, it is easier to manufacture, transport, and install.

[Brief explanation of drawings]

FIG. 1 is a perspective explanatory view of a heat exchange section of a cylindrical open rack type evaporator according to the present invention, and FIGS. 2A and 2B are longitudinal and cross-sectional explanatory views of the exchange section. Figure 3 a, b
The figure is a longitudinal cross-sectional view showing the configuration of a water sprinkler of a cylindrical open rack type evaporator according to the present invention. FIG. 4 is a perspective explanatory view showing an example of a combination of open rack type evaporators according to the present invention. 1.1a... Heat exchange section, 2... Fin tube, 3
...Fin, 4...Lower header tank, 5...
Upper header tank, 6,7.10...water sprinkler, 6a
...Annular trough, 6b...Circular trough, 6c...
Drain, 7a... Groove, 8.9... Manifold.

Claims (1)

[Claims] 1. Fin tubes are arranged in a row in a cylindrical shape, annular header tanks are provided at the upper and lower ends to constitute a heat exchange section, and a heat medium is sprinkled to evaporate the liquefied gas in the tubes. A cylindrical open rack type evaporator characterized in that a water sprinkler is disposed above the heat exchange section.