JP2017106655A - Heat exchanger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat exchanger allowing for improvement of its heat exchange efficiency by preventing freezing of a heat exchange medium.SOLUTION: A heat exchanger employs a configuration that comprises: a body part 10 accommodating a plurality of heat exchanger tubes 11 through which fluid 2 flows; a barrier plate 20 for dividing a heat exchange flow passage 4 through which a heat exchange medium 3 flows and which is formed between the plurality of heat exchanger tubes 11 formed in the interior of the body part 10; a first heat exchange medium supply part 30 for supplying a first heat exchange medium 3A with a first freezing point to a first heat exchange flow passage 4A on the downstream side of the plurality of heat exchanger tubes 11 out of the heat exchange flow passage 4 divided by the barrier plate 20; and a second heat exchange medium supply part 40 for supplying a second heat exchange medium 3B with a second freezing point, which is lower than the first freezing point, to a second heat exchange flow passage 4B on the upstream side of the plurality of heat exchanger tubes 11 out of the heat exchange flow passage 4 divided by the barrier plate 20.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a heat exchanger.

  The following Patent Document 1 discloses a method and an apparatus for regasifying LNG on an LNG carrier that conveys liquefied natural gas (hereinafter referred to as LNG). For regasification of LNG, a heat exchanger such as an open rack type or a shell and tube type is used. An open rack heat exchanger is a large heat exchanger that takes in seawater as a heat exchange medium, and has problems such as seawater corrosion of pipes and the installation of filters that remove foreign substances from seawater, and is not suitable for LNG vaporizers. There is also a case. In this case, a shell and tube type heat exchanger that circulates a heat exchange medium in a closed loop is usually used as the heat exchanger for LNG vaporization.

JP 2005-521849 A

  By the way, the shell-and-tube heat exchanger for regasifying LNG is mainly one that uses an ethylene glycol aqueous solution (hereinafter referred to as EGW) as a heat exchange medium. However, the freezing point of EGW is about −22 ° C. at a 36% weight concentration. When EGW exchanges heat with LNG at an extremely low temperature (about −162 ° C.), there is a concern that it freezes inside the main body (shell). For this reason, conventionally, a design that sacrifices heat exchange efficiency (for example, LNG and EGW in parallel flow) has been performed.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a heat exchanger that can prevent the heat exchange medium from freezing and improve the heat exchange efficiency.

  In order to solve the above-described problems, the present invention provides a heat exchange medium between a main body portion that accommodates a plurality of heat transfer tubes through which a fluid flows and the plurality of heat transfer tubes formed inside the main body portion. A first partition having a first freezing point in a first heat exchange channel downstream of the plurality of heat transfer tubes among the partition walls dividing the circulating heat exchange channel and the heat exchange channels divided by the partition wall. Of the heat exchange flow path divided by the first heat exchange medium supply section for supplying the heat exchange medium and the partition wall, the first solidification point is provided in the second heat exchange flow path upstream of the plurality of heat transfer tubes. And a second heat exchange medium supply unit that supplies a second heat exchange medium having a lower second freezing point.

  Moreover, in this invention, it has a vaporizer which vaporizes the said 2nd heat exchange medium condensed by the heat exchange in the said 2nd heat exchange flow path, and the said 2nd heat exchange medium supply part vaporizes by the said vaporizer. A configuration is adopted in which the second heat exchange medium is provided with a second heat exchange medium circulation channel that supplies the second heat exchange channel to the second heat exchange channel again.

  Further, in the present invention, the vaporizer is inserted into a storage part for storing the condensed second heat exchange medium, and a liquid surface of the second heat exchange medium stored in the storage part, And a water sealing plate that prevents backflow of the vaporized second heat exchange medium to the second heat exchange flow path.

  In the present invention, the vaporizer is connected to a bottom portion of the second heat exchange channel, and the second heat exchange channel circulates the second heat exchange medium and condenses the second heat exchange channel. A configuration is adopted in which a plurality of baffle plates having an inclination for guiding the second heat exchange medium to the bottom portion are provided.

  Further, in the present invention, the first heat exchange medium supply unit supplies the first heat exchange medium after heat exchange in the first heat exchange channel to the first heat exchange channel again. 1 heat exchange medium circulation flow path, a first heat exchange medium heating section for heating the first heat exchange medium in the first heat exchange medium circulation path, and the first heat exchange medium heating section heated by the first heat exchange medium heating section. A configuration is adopted in which a part of one heat exchange medium has a bypass flow path that supplies the vaporizer as a heat exchange medium that vaporizes the second heat exchange medium.

  In the present invention, the partition wall protrudes into at least one of the first heat exchange flow path and the second heat exchange flow path, and transfers between the first heat exchange medium and the second heat exchange medium. The structure of having a protrusion that promotes heat is adopted.

In the present invention, the heat exchange flow path formed inside the main body that accommodates the plurality of heat transfer tubes is divided by the partition wall, and the first side is the downstream side of the plurality of heat transfer tubes (fluid outflow side (high temperature)). Heat exchange is performed by a first heat exchange medium having a freezing point, and heat exchange is performed by a second heat exchange medium having a second freezing point lower than the first freezing point on the upstream side (fluid inflow side (low temperature)) of the plurality of heat transfer tubes. To do. Thus, freezing of the heat exchange medium can be prevented by using the second heat exchange medium having a low freezing point on the upstream side of the plurality of heat transfer tubes having a low fluid temperature. For this reason, the concern about the freezing of the heat exchange medium is solved, and the heat exchange efficiency can be improved.
Therefore, in the present invention, a heat exchanger capable of preventing the heat exchange medium from freezing and improving the heat exchange efficiency can be obtained.

It is a block diagram of the heat exchanger in embodiment of this invention. It is a block diagram of the heat exchanger in another embodiment of this invention.

  Embodiments of the present invention will be described below with reference to the drawings.

Drawing 1 is a lineblock diagram of heat exchanger 1 in an embodiment of the present invention.
As shown in FIG. 1, the heat exchanger 1 includes a main body 10, a partition wall 20, a first heat exchange medium supply unit 30, and a second heat exchange medium supply unit 40. The heat exchanger 1 is a shell-and-tube heat exchanger that heats the fluid 2 to a predetermined temperature by heat exchange with the heat exchange medium 3. The fluid 2 of the present embodiment is LNG and is discharged from the main body 10 as natural gas (hereinafter referred to as NG) by heat exchange with the heat exchange medium 3.

  The main body 10 has a substantially cylindrical shape standing in the vertical direction. The main body 10 accommodates a plurality of heat transfer tubes 11 through which the fluid 2 flows. The plurality of heat transfer tubes 11 extend in the vertical direction, and both ends thereof are supported by the tube plate 12. The tube plate 12 is a disc member fixed to the inner wall surface of the main body 10, and a plurality of through holes for fixing the end portions of the plurality of heat transfer tubes 11 are formed on the plate surface. A space surrounded by the main body 10, the plurality of heat transfer tubes 11, and the upper and lower tube plates 12 serves as a heat exchange channel 4 through which the heat exchange medium 3 flows.

  A fluid inlet 13 through which the fluid 2 flows is provided at the bottom of the main body 10. A fluid outlet 14 through which the fluid 2 flows out is provided at the top of the main body 10. The fluid 2 that has flowed into the main body 10 from the fluid inlet 13 rises in the plurality of heat transfer tubes 11 supported by the tube plate 12, exchanges heat with the heat exchange medium 3, and then passes through the fluid outlet 14. It is discharged from the top of the main body portion 10 through.

  The partition wall 20 is provided inside the main body 10 and divides the heat exchange flow path 4 vertically. The partition wall 20 is a disk member fixed to the inner wall surface of the middle part of the main body 10, and a plurality of through holes through which the plurality of heat transfer tubes 11 are inserted are formed on the plate surface. A space between the through hole of the partition wall 20 and the plurality of heat transfer tubes 11 is sealed by welding or the like.

  The upper half space surrounded by the main body 10, the plurality of heat transfer tubes 11, the upper tube plate 12, and the partition wall 20 is provided with a first heat exchange channel 4 </ b> A through which a first heat exchange medium 3 </ b> A described later flows. Become. The lower half space surrounded by the main body 10, the plurality of heat transfer tubes 11, the lower tube sheet 12, and the partition walls 20 is a second heat exchange flow through which a second heat exchange medium 3B, which will be described later, flows. It becomes road 4B.

  The first heat exchange medium supply unit 30 supplies the first heat exchange medium 3A having the first freezing point to the first heat exchange flow path 4A. As the first heat exchange medium 3A, a liquid medium whose phase does not change in the first heat exchange flow path 4A is used. The first heat exchange medium 3A of the present embodiment is EGW, and its first freezing point is about −22 ° C. at a 36% weight concentration.

  The first heat exchange medium supply unit 30 includes a first heat exchange medium circulation channel 31, a first heat exchange medium heating unit 32, and a bypass channel 33. The first heat exchange medium supply unit 30 includes a pump (not shown) that circulates the first heat exchange medium 3A.

  The first heat exchange medium circulation channel 31 is a channel that supplies the first heat exchange medium 3A after heat exchange in the first heat exchange channel 4A to the first heat exchange channel 4A again. The main body 10 is provided with a first heat exchange medium inflow port 15 in the upper part and a first heat exchange medium outflow port 16 in the middle part above the partition wall 20. The first heat exchange medium circulation passage 31 connects the first heat exchange medium outlet 16 to the first heat exchange medium inlet 15 to form a closed loop of the first heat exchange medium 3A.

  The first heat exchange medium heating unit 32 is a heater that heats the first heat exchange medium in the first heat exchange medium circulation path. For example, an air fan heater can be used as the first heat exchange medium heating unit 32.

  The bypass flow path 33 is a flow path for supplying a part of the first heat exchange medium 3A heated by the first heat exchange medium heating unit 32 to the vaporizer 50 described later. The bypass flow path 33 branches from the first heat exchange medium circulation flow path 31 between the first heat exchange medium heating unit 32 and the first heat exchange medium inflow port 15 to vaporize the first heat exchange medium 3A. 50, and the first heat exchange medium 3A after passing through the vaporizer 50 is supplied to the first heat exchange medium circulating flow between the first heat exchange medium outlet 16 and the first heat exchange medium heating unit 32. Merge into the road 31.

  The second heat exchange medium supply unit 40 supplies the second heat exchange medium 3B having the second freezing point to the second heat exchange channel 4B. As the second heat exchange medium 3B, a condensable medium whose phase is changed from gas to liquid in the second heat exchange flow path 4B is used. The second heat exchange medium 3B of the present embodiment is propane, and its second freezing point is about -187 ° C lower than the first freezing point (about -22 ° C) described above.

  A vaporizer 50 is attached to the main body 10 for vaporizing the second heat exchange medium 3B condensed by heat exchange in the second heat exchange flow path 4B. The second heat exchange medium supply unit 40 includes a second heat exchange medium circulation channel 41. In addition, the second heat exchange medium supply unit 40 includes a blower (not shown) that circulates the second heat exchange medium 3B.

  The second heat exchange medium circulation channel 41 is a channel for supplying the second heat exchange medium 3B vaporized by the vaporizer 50 to the second heat exchange channel 4B again. The main body 10 is provided with a second heat exchange medium inlet 17 in the middle part below the partition wall 20, and a second heat exchange medium outlet 18 is provided in the attached vaporizer 50. The second heat exchange medium circulation channel 41 connects the second heat exchange medium outlet 18 to the second heat exchange medium inlet 17 to form a closed loop of the second heat exchange medium 3B.

The vaporizer 50 includes a reservoir 51 and a water sealing plate 52.
The reservoir 51 stores the condensed second heat exchange medium 3B, and is connected to the bottom 4B1 of the second heat exchange flow path 4B. The lower surface of the bottom portion 4B1 of the second heat exchange flow path 4B is formed by the lower tube plate 12, and the storage portion 51 stores the second heat exchange medium 3B dripping from the lower tube plate 12. It has a configuration.

  A heat transfer tube 53 is accommodated in the reservoir 51. The heat transfer tube 53 is formed in a coil shape. The first heat exchange medium 3 </ b> A is supplied to the heat transfer tube 53 via the bypass flow path 33. The first heat exchange medium 3A supplied to the heat transfer tube 53 is used as a heat exchange medium for vaporizing the condensed second heat exchange medium 3B.

  The water sealing plate 52 is inserted into the liquid surface 3B1 of the second heat exchange medium 3B stored in the storage part 51, and prevents the backflow of the vaporized second heat exchange medium 3B to the second heat exchange flow path 4B. Is. The water sealing plate 52 surrounds the heat transfer tube 53 and allows the space above the heat transfer tube 53 and the second heat exchange medium outlet 18 to communicate with each other, while the space above the heat transfer tube 53 and the second heat exchange channel 4B. Cut between the edges.

  The heat exchange flow path 4 has a plurality of baffle plates 5 for circulating the heat exchange medium 3. The baffle plate 5 has a notch 5a. The plurality of baffle plates 5 are provided in the main body portion 10 so as to be spaced apart in the vertical direction, and the notch portions 5a are alternately arranged on the left and right sides. For this reason, the heat exchange medium 3 can circulate in the main body 10 while bypassing the baffle plate 5.

  The baffle plate 5B of the second heat exchange channel 4B is disposed inclined from the horizontal plane. The baffle plate 5B has a slope that guides the condensed second heat exchange medium 3B to the bottom 4B1 of the second heat exchange flow path 4B. If the inclination of the baffle plate 5B is too large, the flow path area in the middle of the second heat exchange flow path 4B becomes narrow. The inclination of the baffle plate 5B is preferably about 5 ° to 15 °, for example, when the horizontal plane is 0 °.

  Then, operation | movement and an effect | action of the heat exchanger 1 of the said structure are demonstrated.

  As shown in FIG. 1, the heat exchange channel 4 formed inside the main body 10 of the heat exchanger 1 is divided into a first heat exchange channel 4A and a second heat exchange channel 4B by a partition wall 20. ing. The first heat exchange medium supply unit 30 supplies the first heat exchange medium 3A having the first freezing point to the first heat exchange flow path 4A and exchanges heat with the fluid 2 flowing downstream of the plurality of heat transfer tubes 11. . The second heat exchange medium supply unit 40 supplies the second heat exchange medium 3B having the second freezing point to the second heat exchange flow path 4B, and the fluid 2 and heat flowing upstream of the plurality of heat transfer tubes 11. Let them exchange.

  The fluid 2 flowing upstream of the plurality of heat transfer tubes 11 is at a lower temperature than the fluid 2 flowing downstream of the plurality of heat transfer tubes 11, but the second freezing point of the second heat exchange medium 3B is the first heat exchange medium. It is lower than the first freezing point of 3A. In the present embodiment, since propane having a freezing point of about −187 ° C. is used as the second heat exchange medium 3B, freezing does not occur even when LNG having a freezing point of about −162 ° C. is used. Thus, freezing of the 2nd heat exchange medium 3B can be prevented by using the 2nd heat exchange medium 3B with a low freezing point in the upstream of the some heat exchanger tube 11 whose fluid 2 is low temperature.

  And since the fear of the freezing of the heat exchange medium 3 (second heat exchange medium 3B) on the upstream side of the plurality of heat transfer tubes 11 is eliminated, the flow of the heat exchange medium 3 inside the main body 10 is all counterflowed. It can be. That is, as shown in FIG. 1, in the first heat exchange channel 4A, the first heat exchange medium 3A is circulated from the downstream side to the upstream side of the plurality of heat transfer tubes 11, and in the second heat exchange channel 4B. Also, the second heat exchange medium 3B can be circulated from the downstream side to the upstream side of the plurality of heat transfer tubes 11. Since the counter flow has a higher heat exchange efficiency than the parallel flow, the heat exchange efficiency can be improved.

  The fluid 2 is vaporized (natural gasification) by the heat of condensation of the second heat exchange medium 3B (propane) on the upstream side of the plurality of heat transfer tubes 11, and the first heat exchange medium 3A ( The temperature is raised to the required temperature by sensible heat of EGW). In this embodiment, it has the vaporizer 50 which vaporizes the 2nd heat exchange medium 3B condensed by the heat exchange in the 2nd heat exchange flow path 4B, and the 2nd heat exchange medium supply part 40 was vaporized by the vaporizer 50. It has the 2nd heat exchange medium circulation channel 41 which supplies the 2nd heat exchange medium 3B to the 2nd heat exchange channel 4B again. Thereby, since the heat of condensation of the second heat exchange medium 3B can be used while forming a closed loop of the second heat exchange medium 3B, it is possible to improve the heat exchange efficiency.

  The vaporizer 50 includes a reservoir 51 for storing the condensed second heat exchange medium 3B, and a water sealing plate 52 inserted into the liquid surface 3B1 of the second heat exchange medium 3B stored in the reservoir 51. Have. According to this configuration, the backflow of the second heat exchange medium 3B vaporized in the storage part 51 to the second heat exchange channel 4B can be prevented.

  The reservoir 51 is connected to the bottom 4B1 of the second heat exchange channel 4B, and the plurality of baffle plates 5B of the second heat exchange channel 4B transfer the condensed second heat exchange medium 3B to the bottom 4B1. Since the second heat exchange medium 3 </ b> B that has condensed is dripped into the reservoir 51, the condensed second heat exchange medium 3 </ b> B is vaporized in the reservoir 51 and automatically circulates in the closed loop. As described above, the second heat exchange medium 3B automatically circulates in the closed loop, so that the blower (not shown) provided in the second heat exchange medium circulation path 41 assists the circulation of the second heat exchange medium 3B. Can be of low output.

  Further, the first heat exchange medium supply unit 30 is a vaporizer that uses a part of the first heat exchange medium 3A heated by the first heat exchange medium heating unit 32 as a heat exchange medium for vaporizing the second heat exchange medium 3B. 50 has a bypass flow path 33 to be supplied to 50. According to this configuration, there is no need to separately prepare a heat source for the vaporizer 50, and the heat exchanger 1 can be simplified, downsized, and reduced in cost.

  Thus, according to the above-described embodiment, heat is generated between the main body 10 that houses the plurality of heat transfer tubes 11 through which the fluid 2 flows and the plurality of heat transfer tubes 11 that are formed inside the main body 10. Of the partition wall 20 dividing the heat exchange channel 4 through which the exchange medium 3 circulates and the heat exchange channel 4 divided by the partition wall 20, the first heat exchange channel 4A on the downstream side of the plurality of heat transfer tubes 11 Of the heat exchange flow path 4 divided by the first heat exchange medium supply unit 30 for supplying the first heat exchange medium 3A having the first freezing point and the partition wall 20, the second heat upstream of the plurality of heat transfer tubes 11 is provided. By adopting a configuration in which the exchange channel 4B has a second heat exchange medium supply unit 40 that supplies a second heat exchange medium 3B having a second freezing point lower than the first freezing point, the heat exchange medium 4 is provided. Can be prevented from freezing and heat exchange efficiency can be improved.

  As mentioned above, although preferred embodiment of this invention was described referring drawings, this invention is not limited to the said embodiment. Various shapes, combinations, and the like of the constituent members shown in the above-described embodiments are examples, and various modifications can be made based on design requirements and the like without departing from the gist of the present invention.

FIG. 2 is a configuration diagram of a heat exchanger 1A according to another embodiment of the present invention.
As shown in FIG. 2, the partition wall 20A of the heat exchanger 1A protrudes into at least one of the first heat exchange flow path 4A and the second heat exchange flow path 4B (both in FIG. 2), and performs the second heat exchange. It has a plurality of protrusions 21 that transfer the heat of the medium 3B to the first heat exchange medium 3A. The first heat exchange medium 3A that flows on the downstream side of the first heat exchange channel 4A (the upper surface of the partition wall 20A) has a low temperature, but the second flow that flows on the upstream side of the second heat exchange channel 4B (the lower surface of the partition wall 20A). Since the heat exchange medium 3B has a high temperature, it is possible to reliably prevent the first heat exchange medium 3A from freezing by actively transferring the heat of the second heat exchange medium 3B to the first heat exchange medium 3A. it can. The plurality of protrusions 21 increase the surface area of the partition wall 20A and promote heat exchange between the first heat exchange medium 3A and the second heat exchange medium 3B. In addition, since the pressure loss will arise when the several protrusion part 21 is high, it is preferable to arrange | position densely, for example as a height of about 10-20 mm.

  For example, in the said embodiment, although EGW was illustrated as 3 A of 1st heat exchange media, you may use seawater, for example.

  For example, in the said embodiment, although the propane was illustrated as 2nd heat exchange medium 3B, you may use a butane, for example.

  For example, although LNG was illustrated as the fluid 2 in the above embodiment, for example, liquefied petroleum gas (LPG), liquid nitrogen, or the like may be used.

DESCRIPTION OF SYMBOLS 1 Heat exchanger 2 Fluid 3 Heat exchange medium 3A 1st heat exchange medium 3B 2nd heat exchange medium 3B1 Liquid level 4 Heat exchange flow path 4A 1st heat exchange flow path 4B 2nd heat exchange flow path 4B1 Bottom 5 Baffle plate 5B Baffle plate 10 Main body 11 Heat transfer tube 20 Partition 30 First heat exchange medium supply section 31 First heat exchange medium circulation path 32 First heat exchange medium heating section 33 Bypass path 40 Second heat exchange medium supply section 41 Second Heat exchange medium circulation channel 50 Vaporizer 51 Reservoir 52 Water seal plate

Claims (6)

A main body that houses a plurality of heat transfer tubes through which fluid flows;
A partition wall that divides a heat exchange channel that is formed inside the main body and through which a heat exchange medium flows between the plurality of heat transfer tubes,
First heat exchange medium supply for supplying a first heat exchange medium having a first freezing point to a first heat exchange path downstream of the plurality of heat transfer tubes among the heat exchange paths divided by the partition walls. And
A second heat exchange medium having a second freezing point lower than the first freezing point is supplied to a second heat exchange channel upstream of the plurality of heat transfer tubes among the heat exchange channels divided by the partition wall. And a second heat exchange medium supply unit. A vaporizer for vaporizing the second heat exchange medium condensed by heat exchange in the second heat exchange flow path;
The second heat exchange medium supply unit has a second heat exchange medium circulation channel that supplies the second heat exchange medium vaporized by the vaporizer to the second heat exchange channel again. The heat exchanger according to claim 1. The vaporizer is
A reservoir for storing the condensed second heat exchange medium;
A water sealing plate that is inserted into the liquid surface of the second heat exchange medium stored in the reservoir and prevents the vaporized second heat exchange medium from flowing back to the second heat exchange flow path. The heat exchanger according to claim 2, wherein the heat exchanger is provided. The vaporizer is connected to the bottom of the second heat exchange flow path;
The second heat exchange flow path has a plurality of baffle plates provided with an inclination for circulating the second heat exchange medium and guiding the condensed second heat exchange medium to the bottom. Item 4. The heat exchanger according to Item 2 or 3. The first heat exchange medium supply unit includes:
A first heat exchange medium circulation passage for supplying the first heat exchange medium after heat exchange in the first heat exchange passage to the first heat exchange passage;
A first heat exchange medium heating section for heating the first heat exchange medium in the first heat exchange medium circulation path;
A bypass passage for supplying a part of the first heat exchange medium heated by the first heat exchange medium heating unit to the vaporizer as a heat exchange medium for vaporizing the second heat exchange medium, The heat exchanger as described in any one of Claims 2-4 characterized by the above-mentioned.   The partition wall protrudes into at least one of the first heat exchange flow path and the second heat exchange flow path, and has a protrusion that promotes heat transfer between the first heat exchange medium and the second heat exchange medium. It has, The heat exchanger as described in any one of Claims 1-5 characterized by the above-mentioned.

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