WO2008038363A1

WO2008038363A1 - Heat exchanger

Info

Publication number: WO2008038363A1
Application number: PCT/JP2006/319272
Authority: WO
Inventors: Hideo Shinozaki; Hiroaki Honda; Yoshitaka Shibuya
Original assignee: Mitsubishi Kakoki Kaisha, Ltd.
Priority date: 2006-09-28
Filing date: 2006-09-28
Publication date: 2008-04-03

Abstract

To prevent a pipe from being corroded by quickly discharging a liquid condensed in the pipe to the outside of the pipe. This heat exchanger, in which fluid return bent parts (21) are provided on one or both sides of a pipeline (20), is formed in a U-shape or zigzag shape in the vertical direction. The straight upper pipe part (23) and straight lower pipe part (25) which are horizontally directed from the fluid return part (21) and disposed on its upper and lower sides are so tilted as to be gradually separated from each other in the direction away from the fluid return part (21).

Description

Specification

Heat exchanger

Technical field

[0001] The present invention relates to a double-tube heat exchanger composed of an outer tube and an inner tube inside the outer tube, or a heat exchanger having a single-tube heat transfer section.

Background art

[0002] Normally, as a heat exchanger for processing a high-temperature and high-pressure fluid, a double-pipe type apparatus comprising an outer tube and an inner tube inside the outer tube is used. One of them is made to flow a high-temperature fluid, and the other is made to flow a low-temperature fluid. For example, there are cases where a gas is allowed to flow through one of the inner pipe and the outer pipe and cooling water is allowed to flow through the other, or a gas is allowed to flow through each of the inner pipe and the outer pipe.

[0003] When sufficient heat exchange is performed with a double-pipe heat exchanger, a predetermined length is required for the total extension of the pipe line, but the space for heat exchange is limited. Therefore, the space for heat exchange itself has been reduced while increasing the total length of the pipe, or the number of parts such as heat exchange joints has been reduced. For example, by making the heat exchange pipes meandering or spiraling, the total length of the pipes can be lengthened and the heat exchange ^^ can be made smaller. (For example, refer to Patent Document 1).

[0004] In the case of a double-tube heat exchanger, for example, when a reaction fluid (gas) is allowed to flow through either the inner tube or the outer tube and cooling water is allowed to flow through the other, the reaction gas may be condensed in the tube. There is. If the liquid that condenses and stays in the pipe becomes corrosive depending on the conditions, the inner pipe or the outer pipe may be corroded by the liquid that stays condensed.

In addition, when a liquid that causes corrosiveness is flowed depending on conditions, the liquid may stay in the pipe when the apparatus is stopped, etc., and the inner pipe or the outer pipe may be corroded.

Furthermore, if the accumulated liquid solidifies and becomes salt, inorganic or organic matter and adheres to the inner wall of the pipe, this scaling will reduce the heat transfer area of the heat exchange ^^ and reduce the efficiency of the heat exchange ^^ Will do.

[0005] By the way, in the case of a conventional double-tube heat exchanger, the straight tube portion is horizontal. As a result, the liquid condensed in the pipe tends to stay in the horizontal straight pipe section, and this liquid is corrosive depending on the conditions.

[0006] In the case of a single-tube heat exchanger, for example, in the case of an evaporation heater having a single-tube heat transfer tube in a heating furnace, the liquid flowing in from the heater inlet is in the middle of the tube. When heated, the outlet power of the heater also becomes steam. When the operation is stopped, the straight pipe in the horizontal section is horizontal, so liquid may stay in the pipe, and the staying liquid will corrode depending on conditions, and the inside of the pipe is corroded. There was the same fear as in the case of double-tube heat exchange. Patent Document 1: Japanese Patent Laid-Open No. 2004-53222

Disclosure of the invention

Problems to be solved by the invention

[0007] The present invention has been made to solve such a conventional problem, and the purpose of the present invention is to quickly discharge the liquid condensed in the pipe out of the pipe without stagnation. An object of the present invention is to provide a heat exchanger that prevents corrosion of the pipe and prevents scaling in the pipe.

Means for solving the problem

[0008] The heat exchanger according to the invention of claim 1 is provided with a fluid return portion that is bent on one side or both sides of the pipe, and is formed in a U-shape or a meandering shape in the vertical direction. V, and the above fluid return part in the container, and a straight upper pipe part arranged vertically in the horizontal direction.

The straight lower piping section is inclined so as to be separated from each other as the fluid return section force increases.

The invention according to claim 2 is the heat exchanger according to claim 1, wherein the pipe is formed by an outer pipe and a double pipe having an inner pipe force provided inside the outer pipe. And The invention described in claim 3 is characterized in that, in the heat exchanger according to claim 1, the pipe is formed by a single-tube heat transfer section.

The invention according to claim 4 is the heat exchanger according to claim 1, 2 or 3, wherein the inclination angle Θ of the straight upper pipe portion and the inclination angle Θ of the straight lower pipe portion with respect to the horizontal line H are

1 2 is defined as 0.5 ° to 3.0 °, respectively. The invention's effect

[0009] The heat exchanger according to the invention of claim 1 is provided with a fluid return portion that is bent on one side or both sides of the pipe, and is formed in a U-shape or a meandering shape in the vertical direction. V, and the above fluid return part in the container, and a straight upper pipe part arranged vertically in the horizontal direction.

In addition, since the linear lower piping section is inclined so as to be separated from each other as the fluid return force increases, the condensed liquid is inclined even if the reaction gas condenses and liquefies in the pipeline. It flows down along the straight piping section. Therefore, the liquid condensed in the pipe line can be quickly discharged out of the pipe through the inclined linear pipe part and the bent fluid return part. For this reason, even if the liquid condensed in the pipe line is corrosive depending on the conditions, the pipe line is less likely to be corroded by the condensed liquid, and the heat exchanger and thus the heat exchange are reduced. It became possible to improve the reliability of the whole apparatus used. In addition, it has become possible to prevent scaling in the pipes and prevent performance degradation of heat exchange.

In addition, the same effect is exhibited also in the case of heat exchange between liquids.

Brief Description of Drawings

FIG. 1 is a front view of heat exchange according to the present invention.

FIG. 2 is a plan view of a heat exchanger according to the present invention.

FIG. 3 is an enlarged cross-sectional view of a main part of a heat exchanger according to the present invention.

FIG. 4 is an enlarged front view of the main part of the heat exchanger according to the present invention.

Explanation of symbols

[0011] 10 heat exchange ^^

20 pipelines

21 Fluid return section

22 Top connection

23 Upper piping section

24 Bottom connection

25 Lower piping section BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

In this embodiment, a double-tube heat exchanger composed of an outer tube and an inner tube inside the outer tube is taken as an example. However, for example, a heat exchanger having a single-tube heat transfer section is also used. It can be applied.

[0013] As shown in FIG. 1, in the double-pipe heat exchanger 10, the pipe line 20 meanders in a zigzag shape. This pipe line 20 is formed by an outer pipe 30 and an inner pipe 40 inside the outer pipe. A fluid inlet 41 is attached to the lower end portion of the inner pipe 40, and a fluid discharge port is attached to the upper end portion of the inner pipe 40. Exit 42 is installed. A fluid inlet 31 is attached to the upper end of the outer tube 30 (see FIG. 2), and a fluid outlet 32 is attached to the lower end of the outer tube 30.

As shown in FIG. 3, the inner tube 40 is provided with a plurality (eg, three) of distance pieces 43 on the outer peripheral surface thereof radially and at equal intervals in the circumferential direction. The distances between the inner tube 40 and the outer tube 30 are maintained at equal intervals by the plurality of distance pieces 43.

As shown in FIG. 1, the conduit 20 is provided with a fluid return portion 21 bent on one side or both sides thereof, and is formed in a U shape or a meandering shape in the vertical direction. Then, linear pipes connected to both ends of the fluid return part 21 are arranged vertically with the axis centering in the horizontal direction, and the upper pipe part 23 is connected to the upper end of the fluid return part 21. The lower piping part 25 is connected to the lower end connection part 24 of the fluid return part 21.

[0016] Furthermore, a straight upper pipe portion 23 connected to the upper end connection portion 22 of the fluid return portion 21 and a straight lower pipe portion connected to the lower end connection portion 24 of the fluid return portion 21. 25 is inclined so as to be separated from each other as the distance from the fluid return portion 21 increases.

Specifically, as shown in FIG. 4, the inclination angle 0 of the straight upper piping part 23 with respect to the horizontal line H is made equal to the inclination angle 0 of the linear lower piping part 25. . But as desired

1 2

Therefore, there is no problem even if the inclination angle 0 of the straight upper piping part 23 with respect to the horizontal line H is different from the inclination angle Θ of the linear lower piping part 25.

2

[0018] Here, the inclination angle Θ of the straight upper piping part 23 and the inclination angle of the linear lower piping part 25

Θ is preferably 0.5 to 3 °, more preferably 1 to 2 °, respectively. [0019] When the inclination angle Θ of the upper piping section 23 and the inclination angle Θ of the lower piping section 25 are less than 0.5 °

1 2

In this case, the liquid condensed in the pipe 20 and thus in the straight upper pipe part 23 or the straight lower pipe part 25 becomes difficult to flow down. On the contrary, if the inclination angle Θ of the upper piping part 23 and the inclination angle Θ of the lower piping part 25 exceed 3 °, the height of the pipe line 20 becomes higher,

2

There is a disadvantage that the device itself becomes large.

[0020] Now, in the above-described double-pipe heat exchanger 10, water W at room temperature is supplied from the fluid inlet 41 provided at the lower end of the inner tube 40, and the fluid is introduced at the upper end of the outer tube 30. When high-pressure and high-temperature modified gas G is supplied from the port 31, water W is heated by the high-pressure and high-temperature modified gas G while passing through the meandering inner tube 40, and is formed as water vapor S at the upper end of the inner tube 40. It is supplied to the next process from the fluid discharge port 42. On the other hand, the high-pressure and high-temperature modified gas G is cooled by water S while passing through the meandering outer tube 30, and becomes a high-pressure and low-temperature modified gas G ′, which is a fluid discharge port 32 provided at the lower end of the outer tube 30. To be supplied to the next process.

[0021] In the above process, a straight upper pipe portion 23 connected to the upper end connection portion 22 of the fluid return portion 21 and a straight lower pipe portion connected to the lower end connection portion 24 of the fluid return portion 21. 25 is inclined so as to be separated from each other as the distance from the fluid return portion 21 increases.When the device is shut down, the gas G 'condenses and becomes liquid, or the water W does not remain. Since it flows down along the straight piping section, it can be discharged quickly without being retained in the pipe.

Industrial applicability

[0022] The heat exchanger of the present invention is particularly useful as a heat exchanger for high-temperature fluids.

Claims

The scope of the claims

[1] A bent fluid return section is provided on one or both sides of the pipe, and is formed in a U-shape or meandering shape in the vertical direction. The heat is characterized in that the linear upper piping section and the linear lower piping section arranged vertically in the direction are inclined so as to be separated from each other as the distance from the fluid return section increases. Exchange

[2] The heat exchanger according to claim 1, wherein the conduit is formed by an outer tube and a double tube having an inner tube force provided inside the outer tube.

[3] The heat exchanger according to claim 1, wherein the pipe line is formed by a single pipe heat transfer section.

[4] The inclination angle Θ of the straight upper pipe portion with respect to the horizontal line H and the inclination angle Θ of the straight lower pipe portion are 0.5 ° to 3.0 °, respectively. Heat exchanger according to 2 or 3