JP2018054216A - Shell-and-tube type heat exchanger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a small-sized shell-and-tube type heat exchanger capable of coping even with expansion/contraction of a tube due to temperature change, easily securing a joint space, and reducing pressure loss.SOLUTION: A shell-and-tube heat exchanger includes a hollow shell 2 through which first fluid passes, and a tube 3 that is arranged in the shell 2 and through which second fluid passes. The tube 3 meanders in a right-left direction and goes downward, and is bridged between the right and left sides of the shell 2. Preferably, on the right and left sides of the shell 2, a hollow header 7 is provided through a partition wall 6, and in order to bridge the right and left headers 7, a plurality of tubes 3 are provided so as to separate from each other in a front-back direction. Then, an end part of each tube 3 is opened into each header 7; on the upper and lower sides of the shell 2, gates 4, 5 for first fluid are respectively provided; and the right and left headers 7, gates 8, 9 for second fluid are respectively provided.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a shell-and-tube heat exchanger configured by housing a tube in a shell.

  Conventionally, various shell-and-tube heat exchangers are known as disclosed in the following patent documents. In the heat exchanger shown in FIG. 1 of Patent Document 1, a straight tubular tube (heat exchange tube 5) is provided so as to bridge the left and right sides of the shell (body 1). On the other hand, in the heat exchanger shown in FIG. 1 of Patent Document 2, a substantially U-shaped tube (2) is provided in the shell (1).

Microfilm of Japanese Utility Model No. 55-62223 (Japanese Utility Model Publication No. 56-162477) (Specification, page 1, line 17-page 2, line 7, FIG. 1) JP-A-50-114657 (first page, lower left column, line 19-lower right column, line 16, FIG. 1)

  When a straight tube is installed on the left and right sides of the shell, it is necessary to lengthen the tube in order to secure a heat transfer area, and an installation space is required. Moreover, when using it in a location where the temperature difference is large, it is necessary to cope with the expansion and contraction of the tube due to a temperature change by, for example, making a part of the tube an expansion and contraction tube.

  On the other hand, when both ends of the U-shaped tube are held on the left and right sides of the shell, the tube can be expanded and contracted, but both ends of the tube are arranged together on one side of the shell, so the joint space with the piping Becomes narrower. In order to cope with this, if the diameter of the tube is reduced, the pressure loss increases.

  Therefore, the problem to be solved by the present invention is a shell-and-tube heat exchanger that is small in size, can cope with expansion and contraction of a tube due to temperature change, can easily secure a joint space, and can reduce pressure loss. It is to provide.

  The present invention has been made to solve the above-mentioned problems. The invention according to claim 1 is a hollow shell through which a first fluid is passed, and a second fluid which is disposed in the shell and through which the second fluid passes. The shell is a shell-and-tube heat exchanger that is stretched to the left and right of the shell while moving downward while meandering from side to side.

  According to the first aspect of the present invention, since the tube is formed to meander from side to side, the heat exchanger is configured in a small size while ensuring a heat transfer area as compared with a simple straight tube. be able to. Further, since the tube is formed to meander from side to side, it can cope with expansion and contraction due to temperature change. Furthermore, since both ends of the tube are arranged separately on the left and right sides of the shell, it is easy to secure a joint space, and it is not necessary to reduce the diameter of the tube, so that pressure loss can be reduced.

  According to a second aspect of the present invention, hollow headers are provided on the left and right sides of the shell via partition walls, and a plurality of the tubes are separated in the front-rear direction so as to bridge the left and right headers. The end of each tube is opened in each header, and a first fluid inlet / outlet is provided above and below the shell, while a second fluid inlet / outlet is provided on the left and right headers. It is a shell and tube type heat exchanger of Claim 1 characterized by the above-mentioned.

  According to the second aspect of the present invention, the header is provided on the left and right sides of the shell, and a plurality of tubes are provided so as to bridge the header, so that space-saving and efficient heat exchange can be achieved. In addition, a plurality of tubes can be bundled together by a header and piped to the outside.

  According to a third aspect of the present invention, the tube extends in a straight tube from one header in the left-right direction toward the other, and then is folded downward in a substantially semicircular arc shape so that the tube is straight in the left-right direction. Is then folded back downward in a substantially semicircular arc shape again, extending in a straight tube shape toward the other in the left-right direction, and connected to the other header in the left-right direction, and the shell has a substantially rectangular shape It is formed, It is a shell and tube type heat exchanger of Claim 2 characterized by the above-mentioned.

  According to the third aspect of the present invention, the tube has a configuration in which the straight tubular portions spaced apart in the vertical direction are connected to each other in a substantially semicircular arc shape alternately on the left and right sides, and secures a heat transfer area while being small. be able to. Further, since the shell is formed in a substantially rectangular shape, the compatibility with the overall shape of the tube described above is good, and the space can be effectively used.

  In the invention according to claim 4, the upper end of the tube is connected to one header in the left-right direction and an inlet for the second fluid is provided, and the lower end of the tube is connected to the other header in the left-right direction. A second fluid outlet is provided, and the shell is provided with a first fluid inlet at a lower part in the left-right direction, and a first fluid outlet is provided at an upper part in the left-right direction. A shell and tube heat exchanger according to claim 2 or claim 3.

  According to the fourth aspect of the present invention, the inlet or outlet of the second fluid to the tube and the outlet or inlet of the first fluid to the shell are arranged close to each other. Thereby, heat exchange with the 1st fluid and the 2nd fluid can be aimed at smoothly. For example, when the high temperature gas as the second fluid is cooled by exchanging heat with the cooling water as the first fluid, the tube on the inlet side of the high temperature gas becomes hot. Therefore, it is easy to lower the temperature of the hot gas, and local boiling and stress corrosion cracking can be prevented.

  Furthermore, the invention according to claim 5 is used for heat exchange between the off-gas of the fuel cell and the cooling water of the off-gas, the cooling water as the first fluid is passed through the shell, and the off-gas as the second fluid is The shell and tube heat exchanger according to any one of claims 1 to 4, wherein the shell and tube heat exchanger is passed through a tube.

  According to the fifth aspect of the present invention, it is possible to perform heat exchange between the off-gas and the cooling water of the fuel cell, thereby cooling the off-gas and heating the cooling water. If the moisture in the offgas is condensed by cooling the offgas, the condensed water can be returned to the fuel cell to achieve water independence. Further, heat recovery can be achieved by using the heat of the offgas for heating the cooling water. The off-gas is passed through the tube, but the tube has a shape that absorbs expansion and contraction accompanying a temperature change.

  According to the shell-and-tube heat exchanger of the present invention, it is small in size and can cope with the expansion and contraction of the tube due to temperature change, it is easy to secure a joint space, and the pressure loss can be reduced.

It is a schematic longitudinal cross-sectional view of the shell and tube type heat exchanger of one Example of this invention. It is a schematic cross-sectional view of the shell and tube heat exchanger of FIG.

Hereinafter, specific embodiments of the present invention will be described in detail with reference to the drawings.
1 and 2 are schematic views of a shell-and-tube heat exchanger 1 according to an embodiment of the present invention. FIG. 1 is a longitudinal sectional view and FIG. 2 is a transverse sectional view.

  The shell-and-tube heat exchanger 1 of the present embodiment includes a hollow container-like shell 2 and a tube 3 disposed in the shell 2.

  Although the shape of the shell 2 is not particularly limited, it is preferably formed in a substantially rectangular hollow box shape. The shell 2 is provided with a first inlet pipe 4 and a first outlet pipe 5 for introducing and leading the first fluid. The first inlet pipe 4 is an inlet pipe for the first fluid into the shell 2 and is connected to the lower end of the shell 2 in this embodiment. On the other hand, the first outlet pipe 5 is an outlet pipe for the first fluid from the shell 2, and is connected to the upper end of the shell 2 in this embodiment.

  In this embodiment, since the shell 2 is formed in a substantially rectangular hollow box shape, the first inlet pipe 4 is connected to the lower wall of the shell 2, while the first outlet pipe 5 is connected to the upper wall of the shell 2. Is done. At that time, the first inlet pipe 4 and the first outlet pipe 5 may be connected to the central portion in the left-right direction of the shell 2, but as described later, heat exchange with the second fluid passed through the tube 3 is performed. In order to perform efficiently, it is preferable to connect to a position shifted to one side in the left-right direction (and a position shifted to the opposite side between the first inlet pipe 4 and the first outlet pipe 5). In addition, with respect to the front-rear direction of the shell 2, the first inlet pipe 4 and the first outlet pipe 5 are connected to the center part in the front-rear direction in the illustrated example, but are connected to positions shifted from each other in the front-rear direction in some cases. May be.

  Hollow headers 7 (7 </ b> A, 7 </ b> B) are provided at both left and right end portions of the shell 2 via partition walls 6. It is preferable that the outer shape (vertical sectional shape in a side view) of the header 7 is the same as that of the shell 2. In other words, the entire shell 2 with the header 7 is formed in a substantially rectangular box shape in this embodiment, and the shell 2 and the header 7 are partitioned by the partition wall 6.

  The tube 3 is composed of a meandering metal tube, and is provided so as to bridge the left and right headers 7. In the present embodiment, a plurality of tubes 3 are provided in parallel spaced apart from each other in the front-rear direction. Each tube 3 is typically the same shape and size. Specifically, each tube 3 is bridged between the left and right partition walls 6 of the shell 2 while moving downward while meandering left and right. At that time, the left and right end portions of each tube 3 pass through the partition wall 6 in an airtight manner and open into the left and right headers 7.

  More specifically, each tube 3 of the present embodiment has a substantially arcuate shape in which a plurality of straight tubular portions 3a that are vertically spaced apart from each other and the ends of adjacent straight tubular portions 3a are alternately connected to the left and right. Part 3b, and these parts are integrally formed by bending a metal tube. One end portion of the straight tubular portion 3a arranged at the uppermost position is connected to one header 7A, and the other end portion of the straight tubular portion 3a arranged at the lowermost position is connected to the other header 7B.

  The number of the straight tubular portions 3a is appropriately set, but is three in the illustrated example in consideration of the pressure loss of the fluid passing through the tube 3 and the like. That is, in the illustrated example, the tube 3 extends straight from one header 7A in the left-right direction to the other (straight tubular portion 3a), and then is folded downward in a substantially semicircular arc (substantially arcuate). 3b) After extending in a straight tube shape toward one side in the left-right direction (straight tube portion 3a), it is folded back again in a substantially semicircular arc shape (substantially arc-shaped portion 3b) and straight toward the other in the left-right direction. It extends in a tubular shape (straight tubular portion 3a) and is connected to the other header 7B in the left-right direction.

  The left and right headers 7 are provided with a second inlet pipe 8 and a second outlet pipe 9 in order to introduce and lead the second fluid to and from each tube 3. The second inlet pipe 8 is an inlet pipe for the second fluid to the header 7 and thus to each tube 3, and is connected to one (left side in FIG. 1) header 7A. The second outlet pipe 9 is an outlet pipe for the second fluid from each tube 3 and the header 7, and is connected to the other header 7B (the right side in FIG. 1). The second inlet pipe 8 and the second outlet pipe 9 are connected to the header 7 on the end surface on the outer side in the left-right direction of the header 7 in the illustrated example. It may be broken.

  In the present embodiment, the first fluid is introduced into the shell 2 from below the shell 2 and led out above the shell 2. Further, the second fluid is introduced into the tube 3 from the header 7A on one side (left side in FIG. 1) and led out from the header 7B on the other side (right side in FIG. 1). The first fluid and the second fluid are not particularly limited. For example, the first fluid is cooling water and the second fluid is high-temperature gas. In any case, in the heat exchanger 1, heat exchange can be performed without mixing the first fluid and the second fluid. Since the first fluid flows through the shell 2 from below to above, the bubbles can be reliably led out of the heat exchanger 1 even when the first fluid is a liquid containing bubbles.

  According to the shell-and-tube heat exchanger 1 of the present embodiment, the tube 3 is formed to meander from side to side, so that heat exchange is ensured while ensuring a heat transfer area as compared with a simple straight tube. The device 1 can be configured in a small size. Moreover, since the tube 3 meanders to the left and right, it can cope with expansion and contraction due to temperature changes. That is, since at least one end portion of each straight tubular portion 3a is not fixed, expansion and contraction is not restricted. Therefore, the tube 3 does not have a bellows-like expansion and contraction tube in part, and changes in temperature. Expansion and contraction is allowed. Furthermore, since both ends of the tube 3 are arranged separately on the left and right sides of the shell 2, it is easy to secure a joint space, and it is not necessary to make the tube 3 small in diameter, so that pressure loss can be reduced.

  By the way, in this embodiment, the upper end of the tube 3 is connected to the header 7A on one side in the left-right direction (left side in FIG. 1), and the second fluid inlet (second inlet pipe 8) is provided. The lower end of the tube 3 is connected to the header 7B (on the right side in FIG. 1) and an outlet for the second fluid (second outlet pipe 9) is provided. On the other hand, the shell 2 is provided with a first fluid inlet (first inlet pipe 4) in the lower part of the other in the left-right direction (right side in FIG. 1), and in the upper part in one side in the left-right direction (left side in FIG. 1) A single fluid outlet (first outlet pipe 5) is provided. In this way, the inlet or outlet of the second fluid to the tube 3 and the outlet or inlet of the first fluid to the shell 2 are configured close to each other. Thereby, heat exchange with the 1st fluid and the 2nd fluid can be aimed at smoothly. For example, when the high temperature gas as the second fluid is cooled by exchanging heat with the cooling water as the first fluid, the tube on the inlet side of the high temperature gas becomes hot. Therefore, it is easy to lower the temperature of the hot gas, and local boiling and stress corrosion cracking can be prevented.

  As a suitable use example of the shell and tube heat exchanger 1 of the present embodiment, the shell and tube heat exchanger 1 can be used for heat exchange between off-gas (exhaust gas) and cooling water in the fuel cell system. For example, in addition to the off-gas heat exchanger in the fuel cell system disclosed as Japanese Patent Application No. 2006-142943, it can be used as various conventionally known off-gas heat exchangers. In that case, the cooling water as the first fluid is introduced from the first inlet pipe 4 into the shell 2 and led out from the first outlet pipe 5. The off-gas as the second fluid is introduced from the second inlet pipe 8 and led out from the second outlet pipe 9 through the tube 3.

  In this case, in the shell-and-tube heat exchanger 1, the off-gas of the fuel cell and the cooling water can be subjected to heat exchange, thereby cooling the off-gas and heating the cooling water. By cooling off-gas, the water in the off-gas is condensed, and the condensed water is returned to the fuel cell from the branch pipe (not shown) of the second outlet pipe 9 (or the header 7B to which it is connected), and water is self-supporting (external The fuel cell can be operated without replenishing water.

  The shell and tube heat exchanger 1 of the present invention is not limited to the configuration of the above embodiment, and can be changed as appropriate. In particular, it comprises a hollow shell 2 through which the first fluid is passed, and a tube 3 which is arranged in the shell 2 and through which the second fluid is passed, and the tube 3 moves downward while meandering left and right. The other configuration can be changed as appropriate as long as it extends across the left and right sides of the shell 2.

  In the embodiment, each tube 3 may be provided with a heat transfer surface expanding member such as a fin, particularly in the straight tubular portion 3a. Furthermore, in the said Example, the straight tubular part 3a of each tube 3 may be formed so that it may incline a little toward the front end side (downstream side) instead of being arrange | positioned horizontally.

  In addition, in the said Example, although the 1st fluid was passed through the shell 2 from the downward | lower direction to the upper part, the 2nd fluid was passed through the tube 3 from the downward | lower direction from the upper direction. Good. That is, the first fluid may be passed through the shell 2 from the top to the bottom, and the second fluid may be passed through the tube 3 from the bottom to the top. In that case, a first inlet pipe 4 is connected to the upper part of the shell 2 and a first outlet pipe 5 is connected to the lower part. In FIG. 1, a second inlet pipe 8 is connected to the right header 7B, and a second outlet pipe 9 is connected to the left header 7A.

DESCRIPTION OF SYMBOLS 1 Shell and tube type heat exchanger 2 Shell 3 Tube (3a: Straight tubular part, 3b: Substantially arc-shaped part)
4 First inlet pipe 5 First outlet pipe 6 Bulkhead 7 Header (7A: one header, 7B: the other header)
8 Second inlet pipe 9 Second outlet pipe

Claims (5)

A hollow shell through which the first fluid is passed, and a tube disposed in the shell and through which the second fluid is passed,
The tube is stretched to the left and right of the shell while moving downward while meandering from side to side. The shell and tube heat exchanger. On the left and right sides of the shell, a hollow header is provided via a partition,
A plurality of the tubes are provided apart from each other in the front-rear direction so as to bridge the left and right headers.
The end of each tube is open in each header,
The shell-and-tube heat exchanger according to claim 1, wherein a first fluid inlet / outlet port is provided above and below the shell, and a second fluid inlet / outlet port is provided on the left and right headers. The tube extends in a straight tube from one header in the left-right direction to the other, and then is folded downward in a substantially semicircular arc shape to extend in a straight tube in one side in the left-right direction. Folded downward in an arc shape, extended in a straight tube toward the other side in the left-right direction, and connected to the other header in the left-right direction,
The shell and tube heat exchanger according to claim 2, wherein the shell is formed in a substantially rectangular shape. The upper end of the tube is connected to one header in the left-right direction and an inlet for the second fluid is provided, and the lower end of the tube is connected to the other header in the left-right direction and the outlet for the second fluid is provided. And
The said shell is provided with the inlet of the 1st fluid in the lower part of the other side of the left-right direction, and the outlet of the 1st fluid is provided in the upper part of one side of the left-right direction. Shell and tube heat exchanger. Used for heat exchange between the off-gas of the fuel cell and the cooling water of the off-gas,
The shell-and-tube heat exchanger according to any one of claims 1 to 4, wherein cooling water as the first fluid is passed through the shell and off-gas as the second fluid is passed through the tube. .

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