JP2007263473A - Shell and tube heat exchanger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the occurrence of problems such as a decrease in the amount of heat exchange with a body side fluid, component fluctuations and inhibition of the flow of a mixed fluid.
SOLUTION: A plurality of heat transfer tubes 25 and tube plates 30 and 31 are accommodated in a shell body 24, and an end portion of each heat transfer tube 25 penetrates a tube plate 30 on a fluid supply side to enter a channel space 27. Facing open, the end face is exposed. The heat transfer tubes 25 are horizontally spaced apart from each other, and a gas-liquid two-phase mixed fluid is supplied to the channel space 27, and a cylinder-side fluid is supplied to the in-cylinder space 29. Heat exchange with fluid. The tube plate 30 is formed with a stepped portion 40 that protrudes from the end face of each heat transfer tube 25 and extends in a direction intersecting with the vertical, and when the droplet of the tube-side fluid adheres to the tube plate 30, The flow direction is changed to a direction intersecting the vertical direction, and more liquid is guided to the heat transfer tube 25.
[Selection] Figure 1

Description

  The present invention relates to a shell and tube heat exchanger.

  FIG. 8 is a cross-sectional view showing a conventional shell-and-tube heat exchanger 1, and this prior art is described in Patent Document 1, for example. In the shell-and-tube heat exchanger 1, a plurality of heat transfer tubes 3 are horizontally accommodated in a shell body 2 at intervals, and both ends are held in the shell body 2 by tube plates 4 and 5, respectively. .

  The space in the shell body 2 is partitioned into two channel spaces 6 and 7 and a body space 8 in which the heat transfer tubes 3 are accommodated by the tube plates 4 and 5. It penetrates the tube plates 4 and 5 and faces the channel spaces 6 and 7 and is open.

  A tube-side fluid is supplied to one channel space 6, and the tube-side fluid passes through each heat transfer tube 3 and exchanges heat with the body-side fluid passing through the body-side space 8, and then to the other channel space 7. It flows out and is led to a subsequent processing facility.

JP 2002-62081 A

  In the prior art, when a gas-liquid two-phase mixed fluid is introduced as a tube-side fluid into one channel space 6 of the shell-and-tube heat exchanger 1, a part of the mixed fluid passes through each heat transfer tube 3 and the other. The high boiling point liquid that has been guided to the channel space 7 and collided with the tube plates 4 and 5 flows down along the surfaces 4a and 5a of the tube plates 4 and 5, and virtually flows under the channel spaces 6 and 7. It stays as shown by lines 10 and 11.

  When the liquids 10 and 11 are retained in the lower portions of the channel spaces 6 and 7 as described above, the heat transfer tubes 3 disposed at the lower portions are closed by the retained liquids 10 and 11, so that the heat exchange amount with the trunk side fluid Problems such as a decrease in the flow rate, fluctuations in the components of the fluid, and obstruction of the flow of the mixed fluid.

  When a low-temperature fluid such as liquefied natural gas (abbreviated as LNG) is used as a cold heat source, the low-temperature fluid may be sprayed in one channel space 6 to be gas-liquid mixed in order to adjust the exchange heat quantity. In such a case, the sprayed droplets are in direct contact with one of the tube plates 4 and the liquid is liable to stay in one of the channel spaces 6, and the amount of heat exchange with the aforementioned trunk side fluid is reduced. There is a problem that problems such as fluctuation of components and obstruction of the flow of the mixed fluid are likely to occur.

  An object of the present invention is to provide a shell-and-tube heat exchanger that can prevent the occurrence of problems such as a decrease in the amount of heat exchange with the cylinder side fluid, fluctuations in the components of the fluid, and inhibition of the flow of the mixed fluid. That is.

The present invention includes a plurality of heat transfer tubes,
A shell body in which each heat transfer tube is accommodated horizontally with a space between each other, and a cylinder side fluid to be heat exchanged by contact with each heat transfer tube is supplied;
A space in the shell body is divided into a channel space to which a pipe-side fluid composed of a gas-liquid two-phase mixed fluid is supplied and a trunk space in which the plurality of heat transfer tubes are accommodated, and an end portion of each heat transfer tube is A tube plate that penetrates through the channel space and opens in an exposed state of the end face,
The tube plate is a shell-and-tube heat exchanger characterized in that a stepped portion that protrudes from the end face of each heat transfer tube and extends in a direction intersecting with the vertical is formed.

  According to the present invention, a plurality of heat transfer tubes and tube sheets are accommodated in the shell body, and the end portions of the heat transfer tubes pass through the tube plates and open to the channel space, and the end surfaces are exposed. Yes. The heat transfer tubes are horizontally spaced from each other, and a gas-liquid two-phase mixed fluid is supplied to the channel space, a cylinder side fluid is supplied to the internal space, and the mixed fluid and the cylinder side fluid are separated from each other. Heat exchange takes place.

  The tube plate is formed with a stepped portion that protrudes from the end face of each heat transfer tube and extends in a direction intersecting with the vertical. By providing such a step portion on the tube plate, when the liquid droplet of the tube side fluid supplied to the channel space adheres to the tube plate, the flow direction of the liquid droplet flowing down the tube plate is in the vertical direction. The amount of liquid staying in the lower part of the channel space is increased by guiding more liquid to the heat transfer tubes disposed above, increasing the amount of inflow of the tube-side fluid into each heat transfer tube. Can be reduced.

  Since the liquid staying in the lower part of the channel space can be reduced in this way, the heat transfer pipe disposed in the lower part is prevented from being blocked by the liquid, and the flow of the pipe side fluid is less likely to be obstructed. A decrease in the amount of heat exchange with the fluid can be reduced, and fluctuations in the components of the fluid can be prevented.

  In the present invention, the channel space is provided with a liquid spraying means for spraying a liquid to be mixed with the tube-side fluid toward the tube plate.

  According to the present invention, since the liquid spraying means is provided in the channel space, by spraying the liquid of the pipe side fluid from the liquid spraying means toward the tube plate, the pipe side supplied to the channel space and the sprayed liquid is supplied. The fluid is gas-liquid mixed, the flow rate of the tube-side fluid guided from the channel space to each heat transfer tube is increased, and the amount of heat exchange can be increased as compared with the case where the liquid is not sprayed from the liquid spraying means. Therefore, the heat exchange amount can be adjusted by changing the spray amount of the liquid sprayed from the liquid spray means.

  According to the present invention, by providing the step portion on the tube plate, the liquid staying in the lower portion of the channel space is reduced, and troubles such as blockage of the heat transfer tube liquid and inhibition of the flow of the tube side fluid do not occur, It is possible to prevent the amount of heat exchange with the trunk side fluid from being lowered, and to prevent fluctuations in the components of the fluid.

  Further, according to the present invention, since the liquid spraying means is provided in the channel space, the heat exchange amount can be adjusted by changing the flow rate of the tube-side fluid led from the channel space to each heat transfer tube.

  FIG. 1 is a partial cross-sectional view showing the vicinity of a tube plate 30 provided on one channel space 27 side of a shell and tube heat exchanger 20 according to an embodiment of the present invention, and FIG. 2 is a shell and tube type. 2 is a cross-sectional view showing the overall configuration of a heat exchanger 20. FIG. The shell-and-tube heat exchanger 20 is accommodated in a hollow shell body 24 in which substantially hemispherical channel portions 22, 23 are formed at both ends of a cylindrical body portion 21, and in the body portion 21 of the shell body 24. A plurality of heat transfer tubes 25, channel spaces 27 and 28 to which a tube-side fluid made of a gas-liquid two-phase mixed fluid is supplied, and the plurality of heat transfer tubes 25 are accommodated in the space in the shell body 24. Provided in a pair of tube plates 30 and 31 through which the end portions of the respective heat transfer tubes 25 penetrate, and one channel space 27 to which the tube-side fluid is supplied, are mixed with the tube-side fluid. And a liquid spray nozzle 32 that is a liquid spraying means for spraying the liquid to be sprayed toward one tube plate 30 that partitions the one channel space 27 and the in-body space 29.

  The pipe-side fluid is a gas-liquid two-phase mixed fluid in which, for example, a liquefied natural gas (abbreviated as LNG) of about −50 ° C. and the vaporized gas are mixed, and the liquid sprayed from the liquid spray nozzle 32 is For example, the liquefied natural gas is about −160 ° C. Further, the cylinder-side fluid supplied to the cylinder space 29 is a medium such as propane gas.

  The liquid spray nozzle 32 is supplied with the liquid from a liquid supply source (not shown), and the amount of heat exchange can be adjusted by controlling the amount of liquid supplied from the liquid supply source to the liquid spray nozzle 32. It is configured.

  The body portion 21 is provided with a supply side pipe joint 35 to which the body side fluid is supplied and a discharge side pipe joint 36 for discharging the body side fluid from the body space 29. One channel portion 22 is provided with a supply side pipe joint 37 to which the pipe side fluid is supplied, and the other channel portion 23 is provided with a discharge side pipe joint 38 for discharging the pipe side fluid.

  The heat transfer tubes 25 are horizontally held in the in-cylinder space 29 by the respective tube plates 30 and 31 so as to be spaced apart from each other, and are supplied to the tube-side fluid in the heat transfer tubes 25 and the in-cylinder space 29. Heat exchange with the fluid can cool the trunk side fluid.

  3 is a perspective view of one tube sheet 30, and FIG. 4 is a partial enlarged front view of the one tube sheet 30 as viewed from the left in FIG. The one tube plate 30 protrudes upstream of the end surface 39 facing the channel space 27 of each heat transfer tube 25 in the flow direction A of the tube side fluid, and intersects the vertical which is the vertical direction in FIG. A plurality of step portions 40 extending in the horizontal direction, which is the direction, are formed. The heat transfer tubes 25 are arranged in a lattice shape, and a stepped portion 40 is integrally formed between the heat transfer tubes 25 adjacent in the vertical direction.

  FIG. 5 is an enlarged cross-sectional view showing a state in which the heat transfer tube 25 is attached to the tube plate 30. Each heat transfer tube 30 has an axial end portion inserted through an insertion hole 43 formed in the tube plate 30, and the periphery of the end surface 39 is welded.

  In the tube sheet 30, the stepped portion 40 is formed by forming the groove 45 by milling on a disk-shaped base material having a thickness of about 2 mm to 3 mm larger than the thickness necessary for strength made of steel. Alternatively, each stepped portion 40 may be separately manufactured as a member independent of the base material using a metal material or a synthetic resin material, and may be attached to the surface of the disk-shaped base material.

  In the shell and tube heat exchanger 20 configured as described above, the tube plate 30 is formed with a stepped portion 40 that protrudes from the end face 39 of each heat transfer tube 25 and extends in a direction intersecting with the vertical. Therefore, when the droplet of the tube-side fluid supplied to the channel space 27 adheres to the tube plate 30, the flow direction of the droplet flowing down the tube plate 30 changes in the horizontal direction along the stepped portion 40, More liquid can be guided to the heat transfer tubes 30 arranged at higher positions to increase the inflow amount of the tube-side fluid into each heat transfer tube 25 and to reduce the liquid staying in the lower portion of the channel space 27. .

  Since the liquid staying in the lower portion of the channel space 27 can be reduced in this way, the heat transfer tube 30 disposed in the lower portion is prevented from being blocked by the liquid, and the flow of the tube side fluid is not hindered. It is possible to reduce a decrease in the amount of heat exchange with the fluid and to prevent fluctuations in fluid components.

  Further, since the liquid spray nozzle 32 is provided in the channel space 27, by spraying the liquid of the tube side fluid from the liquid spray nozzle 32 toward the tube plate 30, the sprayed liquid and the pipe supplied to the channel space 27. The side fluid is gas-liquid mixed to increase the flow rate of the tube side fluid guided from the channel space 27 to each heat transfer tube 30, and the heat exchange amount is increased compared to the case where the liquid is not sprayed from the liquid spray nozzle 32, Alternatively, the amount of heat exchange can be adjusted by reducing the amount of heat exchange by reducing the amount of spray and thus changing the amount of liquid sprayed from the liquid spray nozzle 32.

  FIG. 6 is a perspective view showing a tube sheet 30a according to another embodiment of the present invention. Note that the same reference numerals are given to the portions corresponding to the above-described embodiment. In this embodiment, when it is difficult to increase the thickness of the tube sheet, when the tube sheet is clad steel, or when the surface is coated for the purpose of anticorrosion, it is made of a separately manufactured metal or synthetic resin Alternatively, a tube plate 30a may be used in which the stepped portion 40 made of an elongated plate or a rod-like body is welded or adhered to the surface of the base material.

  FIG. 7 is a partial enlarged front view showing a tube sheet 30b according to still another embodiment of the present invention. In the present embodiment, the step portion 40 is formed to be inclined at a predetermined angle θ with respect to the vertical direction which is the vertical direction in FIG. This angle θ is an angle intersecting with the vertical and is selected to be 45 °, for example, but may be appropriately set in a range of 0 ° <θ <90 ° depending on the arrangement of the heat transfer tubes 25.

FIG. 3 is a partial cross-sectional view showing the vicinity of a tube plate 30 provided on one channel space 27 side of the shell-and-tube heat exchanger 20 according to the embodiment of the present invention. 2 is a cross-sectional view showing the overall configuration of a shell-and-tube heat exchanger 20. FIG. 3 is a perspective view of one tube sheet 30. FIG. FIG. 3 is a partial enlarged front view of one tube sheet 30 as viewed from the left in FIG. 2. It is an expanded sectional view which shows the attachment state to the tube plate 30 of the heat exchanger tube 25. FIG. It is a perspective view which shows the tube sheet 30a of other form of implementation of this invention. It is a partial enlarged front view which shows the tube sheet 30b of further another form of implementation of this invention. It is sectional drawing which shows the conventional shell and tube type heat exchanger 1. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 20 Shell and tube type heat exchanger 21 Body part 22, 23 Channel part 24 Shell main body 25 Heat-transfer tube 27, 28 Channel space 29 Body space 30, 31 Tube plate 32 Liquid spray nozzle 40 Step part

Claims (2)

A plurality of heat transfer tubes;
A shell body in which each heat transfer tube is accommodated horizontally with a space between each other, and a cylinder side fluid to be heat exchanged by contact with each heat transfer tube is supplied;
A space in the shell body is divided into a channel space to which a pipe-side fluid composed of a gas-liquid two-phase mixed fluid is supplied and a trunk space in which the plurality of heat transfer tubes are accommodated, and an end portion of each heat transfer tube is A tube plate that penetrates through the channel space and opens in an exposed state of the end face,
A shell-and-tube heat exchanger, wherein the tube plate is formed with a step portion that protrudes from the end face of each heat transfer tube and extends in a direction intersecting with the vertical.   The shell-and-tube heat exchanger according to claim 1, wherein the channel space is provided with a liquid spraying means for spraying a liquid to be mixed with the tube-side fluid toward the tube plate.

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