JPS6219676B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a heat exchanger and a method for manufacturing the same, and more particularly to a shell-and-tube heat exchanger and a method for manufacturing the same.

An example of a shell-and-tube heat exchanger is JP-A-53-140653.
Publication No. 145145, Japanese Patent Application Publication No. 1983-145145, Japanese Patent Application Publication No. 1983-
As shown in Publication No. 146355, etc., a heat exchange element in which a U-shaped or straight heat exchanger tube is supported by a tube plate is housed in the shell, and one side of the fluid is allowed to flow inside the shell, while the other is adjacent to the tube plate. The other fluid is caused to flow into the heat transfer tube from the water chamber provided in the heat transfer tube, thereby performing heat exchange between the two fluids.

In these multi-tubular heat exchangers, a partition plate is provided in the water chamber to partition the water chamber into a heat tube inlet side and a heat tube outlet side. However, this partition plate is fixed to the tube plate, and since holes for heat transfer tubes cannot be provided in the tube plate where the partition plate is fixed, the heat transfer tubes themselves are not attached. Therefore, the heat exchanger tube bundle has gaps at the locations where the partition plates are provided. For this reason, the fluid flowing between the heat exchanger tubes, that is, the shell side fluid, flows more through the gap where resistance is lower than through the heat exchanger tube bundle, and the heat exchange efficiency of the heat exchanger decreases.

In order to solve the above-mentioned problems, improved heat exchangers are provided with flow prevention plates in the gaps between the heat exchanger tube bundles. However, the inventor believes that because the flowbreak plate itself is a heavy object and is subject to a large resistance force from the flow on the body side, the flowbreak plate itself or the support rod supporting it may flex, causing vibrations. I found something to see. Furthermore, studies by the inventors have revealed that there is a problem in that fluid accumulates in the gap between the flowbreak plates and the drain does not drain completely.

An object of the present invention is to maintain a substantially constant flow of the fluid flowing between the heat exchanger tubes, that is, the fluid on the shell side, to achieve a good heat exchange efficiency and prevention of vibration of the heat exchanger tubes.

The feature of the present invention is that in conventional heat exchangers, holes are not drilled in the tube plate because of the partition plate.
A simulated tube was installed in a place where a heat transfer tube was not installed, and the fluid flow on the shell side was made almost constant.

Furthermore, the second and third inventions are characterized by a heat exchanger structure suitable for manufacture and a manufacturing method, respectively.

Hereinafter, the present invention will be explained in detail based on the drawings.

1 and 2 show a heat exchanger.
In the figure, the water chamber 1 of the heat exchanger divides the water chamber side fluid a that flows in from the water chamber side inlet nozzle 2 into the heat transfer tube 4, collects it in the water chamber again, and sends it from the water chamber side outlet nozzle 3. The water chamber 1 is partitioned by a partition plate 5 to allow water to flow out. On the other hand, on the shell side, the shell side fluid b flows from the shell side inlet nozzle stub 6 and contacts the outer surface of the heat transfer tube while bending the flow between appropriately arranged baffle plates 8, and after performing a predetermined heat exchange. The structure is such that the water flows out from the shell side outlet nozzle.

By the way, in the above-mentioned heat exchanger, in order to increase the heat exchange efficiency, the fluid flowing through the heat exchange element is folded to increase the moving distance within the heat exchanger tube. FIGS. 3 to 5 show examples of this, where A shows a sectional view from the water chamber side and B shows a sectional view from the barrel side. In the examples shown in Figures 3 and 4, the fluid a on the water chamber side is 4
In the example shown in FIG. 5, there are two directions.
Further, in the example shown in FIG. 3, the fluid on the shell side is also a two-fold flow, and the rest is a transient flow similar to that shown in FIG.

As mentioned above, the water chamber 1 is divided into a plurality of chambers in consideration of diversion, and this division is performed by the partition plate 5. However, since the partition plate 5 closes the holes provided in the tube sheet 9 that communicate with the heat exchanger tubes 4, no holes can be provided and the heat exchanger tubes 4 cannot be arranged. Therefore, a gap c as shown in FIG. 2 is created between the bundles of heat exchanger tubes. For this reason, more of the body-side fluid b flows through the gap c where the resistance is lower than through the heat exchanger tube bundle, resulting in a decrease in the heat exchange efficiency. Therefore, in this embodiment, the dummy tube 12 is placed in the gap c between the heat transfer tube bundles. Simulated tube 1
2, the same arrangement of heat exchanger tubes as the heat exchanger tube arrangement in the heat exchanger tube bundle is used. The gap c in the heat exchanger tube bundle due to the provision of the partition plate 5 exists in the cross direction in the case of four-fold flow, but in the simulated tube 12, it exists in the direction in which the body side fluid b flows across the heat exchanger tubes 4. It is sufficient to provide it in the gap.

In this embodiment, the shell-side fluid b enters the heat exchange element in the shell from the shell-side inlet nozzle stub 6, passes through the tube bundle composed of the heat transfer tubes 4 and the simulated tubes 12, and passes through the arrows o,
Although the flow is bent within the heat transfer element according to p, q, r, s, and t, it flows almost uniformly. Therefore, heat exchange is performed almost equally in each heat exchanger tube, making it possible to obtain a high heat exchange rate. Furthermore, since there is no non-uniform high-speed flow, the risk of vibration occurring in the heat exchanger tubes is extremely small.

The present invention will be explained in more detail below using highly preferred examples.

The heat exchanger shown in Figures 6 to 11 uses straight heat exchanger tubes, and is extremely suitable as a large-scale heat exchanger in which the water chamber side fluid a has a 4-fold flow and the shell side fluid has a 2-fold flow. It is something. The structure of the water chamber 1 of this embodiment is the same as the example shown in FIG. 6, except for the structure on the body side.
In this embodiment, the heat exchanger tube 4 is supported at both ends by two tube sheets, a front tube sheet 9a and a rear tube sheet 9b, and a heat exchange element is formed between the two tube sheets. . As shown in FIG. 7, the heat exchange element includes a heat exchanger tube bundle 18 provided in a cylindrical body plate 14,
A fixing rod 15 for fixing the baffle plate is provided at a predetermined position of the heat exchanger tube bundle. Of course, the heat exchanger tubes 4 cannot be provided at the position where the partition plate 5 on the water chamber side is provided, and a gap is created. Therefore, in this embodiment, by utilizing the horizontal gap, the body side fluid b
A partition plate 16 is provided to divert the flow. On the other hand, a dummy pipe 12 is provided in the vertical gap as shown in FIG. It is already well known that arranging the heat transfer tubes 4 in positions forming an equilateral triangle is effective in improving the heat exchange efficiency of the heat exchanger. It is effective to equalize the flow. This is because the same arrangement is achieved between the heat transfer tube and the simulated tube. For this reason, both the heat exchanger tubes 4 and the dummy tubes 12 are arranged so that their axial centers are located on the intersection of the alignment lines X and Y. Of course, the same applies to the fixed rod 15. Furthermore, on the above alignment line,
In order to arrange the heat exchanger tubes 4 and the simulated tubes 12, consideration is also given to the gaps between the heat exchanger tube bundles 18. That is, the gap is defined so that the heat exchanger tubes of other heat exchanger tube bundles are located at positions separated by an integral multiple of the pitch of the heat exchanger tubes 4 on the alignment lines X and Y.

The dummy tube 12 is attached by welding the tube 12 to a support 13 screwed onto the body side of the front tube plate 9a. Further, the length of the dummy tube 12 is up to the baffle plate 8 closest to the rear tube plate 9b. This is because the simulated tube cannot be supported by the rear tube plate 9b. In addition, the rear tube plate 9
A rear water chamber 18 is provided on the opposite side of b to divert the water chamber side fluid a.

The heat exchanger according to this embodiment not only provides the same effects as the embodiment shown in FIG. 1, but also has the advantage that since the heat exchanger tubes 4 are straight tubes, the simulated tubes 12 can also be straight tubes. Additionally, since the heat exchange element can be separated into the front and rear water chambers, it is easy to remove deposits from the pipes.

Next, a method for manufacturing the heat exchange element of the heat exchanger according to this embodiment will be explained based on FIG. 10.

First step: Machining holes for heat transfer tubes and screw holes for dummy tubes and fixing rods in the front tube plate 9a, and fabricating holes for heat transfer tubes in the rear tube plate 9b.

2nd process Weld the body plate 14 to the front tube plate 9a.

Next, the imitation tube 12 with the fixing rod 15 and the support body 13 welded thereon is screwed into the front tube plate 9a.

Third step: Put a spacer 19 of a predetermined size into the fixing rod 15,
The baffle plate 8 is inserted while maintaining a predetermined distance by this spacer.

Fourth step: Spacers 19 and buffle plates 8 are inserted alternately, and after the last buffle plate 8E is inserted, it is fastened to the fixing rod with nuts 17.

Next, the simulated pipe 12 and the full plate 8E are welded together to prevent rotation.

Fifth step: The guide rod 20 is connected to the front tube plate 9a, the buttful plate 8 (8
E) and the rear tube plate 9b, and weld the rear tube plate 9b to the body plate 14 so that the center of the heat exchanger tube insertion does not shift.

Sixth step: The guide rod 20 is pulled out, and then the heat exchanger tube 4 is inserted and fixed to the tube sheets 9a, 9b by expansion, welding, or the like.

As is clear from the above process, the installation of the simulated tube not only does not have any adverse effect on the heat exchange element manufacturing process, but also the simulated tube plays a part of the role of a fixing rod. Therefore, it is also effective in reducing the number of fixing rods.

As described above, according to the present invention, it is possible to reliably prevent the drift that occurs in the flow outside the heat exchanger tube flowing through the heat exchange element, and therefore, it is possible to improve the heat exchange efficiency and prevent the flow from occurring in the heat exchanger. It also has the effect of suppressing the vibrations that tend to occur.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal cross-sectional view of a heat exchanger according to an embodiment of the present invention, Fig. 2 is a cross-sectional view taken from Fig. 1, and Figs. 3 to 5 are diagrams illustrating various types of heat exchangers. , 6th
The figure is a longitudinal cross-sectional view of a heat exchanger according to a preferred embodiment of the present invention, FIG. 7 is a cross-sectional view of its heat exchange element, FIG. 8 is a partially enlarged view of FIG. 7, and FIG. A detailed view of the simulated tube used, and FIG. 10, is an explanatory view of manufacturing the heat exchange element. 1... Water chamber, 4... Heat exchanger tube, 5... Partition plate,
8... Buff full plate, 9... Tube sheet, 12... Simulated tube, 13... Tube support, 15... Fixed rod, 17...
...Natsuto.

Claims (1)

[Scope of Claims] 1. A pressure vessel, a tube plate that divides the pressure vessel into a water chamber side and a body side, a partition plate that is fixed to the tube plate and divides the water chamber side into a plurality of water chambers, and A heat exchanger comprising a plurality of heat transfer tubes provided on the body side communicating with the water chamber through holes drilled in the tube sheet, wherein the heat exchanger tubes are provided on the body side of the tube sheet and are connected to the partition plate. A heat exchanger characterized in that a large number of simulated tubes are provided in parallel with the heat transfer tubes at opposing positions. 2. The heat exchanger according to claim 1, wherein the simulated tube has the same diameter as the heat transfer tube. 3. The heat exchanger according to claim 1 or 2, wherein the simulated tubes are arranged on an alignment line determined by the arrangement of the heat exchanger tubes. 4. The heat exchanger according to claim 1, 2, or 3, wherein the gap between the heat exchanger tubes created by the partition plate is an integral multiple of the heat exchanger tube arrangement pitch. vessel. 5 A pressure vessel, a tube plate that divides the pressure vessel into a water chamber side and a body side, a partition plate that is fixed to the tube plate and divides the water chamber side into a plurality of water chambers, and a partition plate that is perforated in the tube plate. In a heat exchanger equipped with a large number of heat transfer tubes provided on the body side communicating with the water chamber through girder holes, the tubes are provided on the body side of the tube sheet and at a position facing the partition plate. A heat exchanger characterized in that a support is embedded, one end of the simulated tube is joined to the tube support, and the other end of the simulated tube is supported by a buttful plate that bends the flow of fluid flowing on the body side. vessel. 6 A pressure vessel, a tube plate that divides the pressure vessel into a water chamber side and a body side, a partition plate that is fixed to the tube plate and divides the water chamber side into a plurality of water chambers, and a partition plate that is perforated in the tube plate. A large number of heat transfer tubes provided on the body side communicating with the water chamber through girder holes, and a large number of simulated tubes provided parallel to the heat transfer tubes on the body side position of the tube sheet facing the partition plate. In manufacturing a heat exchanger equipped with the above, a simulated tube is fixed in advance to the above position of the tube sheet, and then the heat exchanger tube is fixed to the tube sheet, and then the tube sheet, the partition plate, and the heat exchanger tube are fixed to the tube sheet. and a method for manufacturing a heat exchanger, characterized in that the entire heat exchange element including the simulated tube is assembled into a pressure vessel.