JP6956491B2 - Heat exchanger and heat exchange system - Google Patents

Description

The present invention relates to heat exchangers and heat exchange systems for heating fluids such as liquefied natural gas.

Generally, when liquefied natural gas (LNG) is used as fuel, LNG stored at a low temperature is heated and vaporized, and in some cases, the vaporized natural gas (NG) is overheated and raised to a required temperature. It needs to be warmed. At this time, as a device for vaporizing and overheating LNG, for example, a heat exchanger of a type called a shell-and-tube type is used (see, for example, Patent Document 1 below).

In this type of heat exchanger, a tube (tube) as a flow path for LNG is housed inside the shell, a heat medium is circulated inside the shell, and the LNG flowing through the tube and the periphery of the tube are circulated. LNG is heated by exchanging heat with the flowing heat medium.

In the following, among a series of steps of heating a heated fluid such as LNG using a heat exchanger, the step of vaporizing the heated fluid in a liquid state is "vaporized", and the heated fluid becomes a gas. The process of further applying heat to raise the temperature is particularly referred to as "overheating".

Japanese Patent Publication No. 2008-518187

In the heat exchanger as described above, specifications such as the diameter and length of pipes, the number of pipes, the distance between pipes, and the size of shells are appropriately determined at the design stage in order to satisfy the required performance. Here, in the case of the conventional shell-and-tube type heat exchanger, each of the pipes forming the LNG flow path is composed of a single pipe from the inlet to the outlet. That is, the diameter and number of each pipe, the distance between the pipes, and the like are the same over the entire flow path from the inlet to the outlet of the shell.

On the other hand, in the heat exchanger used for vaporizing LNG, the amount of heat exchange per unit length in the upstream flow path and the amount of heat exchange per unit length in the downstream flow path are significantly different. On the upstream side, the amount of heat exchange is large because the heat of vaporization is taken from the heat medium in the process of vaporizing the liquid LNG to NG, but on the downstream side, the process of overheating the already vaporized NG is performed, so the upstream side The amount of heat exchange is small compared to.

However, as described above, the configuration of the flow path depending on the diameter and arrangement of the pipes is the same on the upstream side and the downstream side, and the performance related to heat exchange in design is not different between the upstream side and the downstream side. Therefore, if the diameter and arrangement of the pipes are determined so as to prevent the heat medium from freezing in consideration of the size of the heat exchange amount on the upstream side, the design performance with respect to the actual heat exchange amount is excessive on the downstream side. Become. On the contrary, if the pipe is designed according to the heat exchange amount on the downstream side, the design performance will be insufficient for the required heat exchange amount on the upstream side, so in the end, on the upstream side. There is no choice but to design the whole according to the amount of heat exchange. In this way, in the conventional shell-and-tube type heat exchanger, the performance related to heat exchange is partially excessive with respect to the required heat exchange amount, and the size of the device is uselessly large. It had been transformed. Increasing the size of the device requires an increase in the size of the installation stand, which leads to an increase in construction costs, and may also cause transportation restrictions such as a limitation on the vehicles that can be loaded.

In view of such circumstances, the present invention aims to provide a heat exchanger and a heat exchange system capable of optimizing the performance related to heat exchange for each part and suppressing the increase in size of the apparatus.

The present invention has passed through a first shell configured to house a first heating line through which a fluid to be heated flows and to supply a heat medium around the first heating line, and the first heating line. Between the first shell and the second shell, which is configured to house a second heating line through which the fluid to be heated flows and to supply a heat medium around the second heating line. It is provided with an intermediate shell that is located and is configured to allow the fluid to be heated to flow through the space provided inside, and the fluid to be heated introduced from the lower part of the first shell into the first heating line is passed through the intermediate shell. The first heating line is configured to be extracted above the second heating line so that the amount of heat exchanged per unit length in the first heating line is larger than the amount of heat exchanged per unit length in the second heating line. At least one of the cross-sectional area of the flow path of the fluid to be heated, the contact area with the heat medium per volume of the fluid to be heated, or the capacity of the heat medium per volume of the fluid to be heated in one shell is from the second shell. It is related to a shell-and-tube type heat exchanger that is configured to be large.

In concretely implementing the heat exchanger of the present invention, the first heating line is configured as a plurality of tubes, the second heating line is configured as one or more tubes, and the first heating line is configured. The number of tubes can be larger than the number of tubes constituting the second heating line.

In concretely implementing the heat exchanger of the present invention, the first heating line and the second heating line are each configured as a plurality of tubes, and the distance between the tubes constituting the first heating line is set to the first. (Ii) It can be set wider than the distance between the pipes constituting the heating line, and the area of the cross section orthogonal to the pipe of the first shell can be set larger than the area of the cross section orthogonal to the pipe of the second shell.

The present invention also provides the heat exchanger according to claim 1, wherein the heat exchanger is provided with at least one of a temperature sensor for detecting the temperature of the fluid to be heated and a pressure sensor for detecting the pressure of the fluid to be heated. It depends on the heat exchange system used.

In the heat exchange system of the present invention, it is preferable that the temperature sensor or the pressure sensor is provided in the intermediate shell.

According to the heat exchanger and the heat exchange system of the present invention, it is possible to achieve an excellent effect that the performance related to heat exchange can be optimized for each part and the size of the apparatus can be suppressed.

It is a front sectional view explaining the form of the heat exchanger according to 1st Example of this invention. It is a front sectional view explaining the form of the heat exchanger according to the 2nd Example of this invention. It is a front sectional view explaining the form of the heat exchanger according to the 3rd Example of this invention. It is a front sectional view explaining the form of the heat exchanger according to the 4th Example of this invention. It is a block diagram explaining an example of the heat exchange system by carrying out this invention.

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

FIG. 1 shows a form of a heat exchanger according to the first embodiment of the present invention. The heat exchanger 1 of the first embodiment is a type classified into a shell-and-tube type, but the shell containing the pipe inside is divided into two stages, an upstream side and a downstream side, and an intermediate shell is further formed between them. It is characterized in that the flow path configuration can be changed by a pipe between the two-stage shells by connecting with.

As shown in FIG. 1, the heat exchanger 1 is similarly heated as the first shell 3 on the upstream side accommodating a plurality of pipes 2 as a first heating line for circulating a fluid L to be heated such as LNG inside. A second shell 5 accommodating a plurality of pipes 4 as a second heating line for circulating the fluid L inside is provided, and the first shell 3 and the second shell 5 are connected by an intermediate shell 6. The heat medium A is introduced into the first shell 3 and the second shell 5, respectively, and the heat medium A introduced into the first shell 3 and the second shell 5 is the tubes 2 and 4. It is supplied to the periphery of the water, contacts the fluid L to be heated via the pipes 2 and 4, and exchanges heat with the fluid L to be heated. The second shell 5 is arranged above the first shell 3 via the intermediate shell 6, and the upstream and downstream pipes 2 and 4 are vertically inside the first shell 3 or the second shell 5, respectively. It is arranged in the direction along the.

The first shell 3 is a hollow member having a cylindrical shape as a whole, and the lower surface of the side surface 3a forming the cylindrical surface is covered with the bottom plate 3b and the upper surface is covered with the upper plate 3c. At appropriate positions on the side surface 3a, a heat medium inlet 3d for introducing the heat medium A into the first shell 3 and a heat medium outlet 3e for deriving the heat medium A from the first shell 3 are provided. .. In the example shown here, the heat medium inlet 3d is provided at one place near the upper end of the side surface 3a, and the heat medium outlet 3e is provided at one place near the lower end on the side opposite to the heat medium inlet 3d with respect to the central axis of the side surface 3a. Is placed.

The pipe 2 constituting the first heating line extends from the bottom plate 3b to the upper plate 3c, and the bottom plate 3b and the upper plate 3c are each penetrated through the end of the pipe 2 provided inside the first shell 3. There is. In this way, the space inside the pipe 2 through which the fluid L to be heated flows and the space inside the first shell 3 through which the heat medium A flows and outside the pipe 2 are isolated from each other.

Inside the first shell 3, two baffle plates 7a and 7b are provided so as to form a surface orthogonal to the pipe 2. Of these, the baffle plate 7a located on the upper side is divided so as to cross the space inside the first shell 3 below the heat medium inlet 3d, and the baffle plate 7a is on the side surface 3a on the heat medium outlet 3e side. The vicinity of the inner wall is not closed, and an opening exists between the inner wall and the inner wall. Further, the baffle plate 7b located on the lower side forms a surface along the horizontal direction above the heat medium outlet 3e to divide the space in the first shell 3, but the side surface 3a on the heat medium inlet 3d side. There is an opening between it and the inner wall. These baffle plates 7a and 7b are penetrated through the pipe 2 at the intersections with the pipes 2 and do not obstruct the flow path of the fluid L to be heated inside the pipe 2. That is, the baffle plates 7a and 7b are installed in the space in the first shell 3 isolated from the space inside the pipe 2.

The heat medium A introduced into the first shell 3 from the heat medium inlet 3d first flows along the horizontal direction in the vicinity of the upper plate 3c in the first shell 3, and the inner wall of the side surface 3a opposite to the heat medium inlet 3d. It flows downward while bypassing the obstruction plate 7a in the vicinity. Further, after flowing horizontally between the baffle plate 7a and the baffle plate 7b toward the heat medium inlet 3d side, it flows downward while bypassing the baffle plate 7b and flows along the horizontal direction near the bottom plate 3b. It reaches the heat medium outlet 3e. In this way, by arranging the baffle plates 7a and 7b alternately with respect to the flow path of the heat medium A in the first shell 3, the heat medium A introduced from the heat medium inlet 3d meanders around the tube 2. At the same time, it leads to the heat medium outlet 3e. By meandering the flow of the heat medium A in this way, the chance that the heat medium A comes into contact with the fluid L to be heated via the tube 2 is increased, and the heat exchange efficiency is improved. Here, as the baffle plate, the case where two baffle plates 7a and 7b are provided in the first shell 3 is illustrated, but the dimensions of the first shell 3, the heat medium inlet 3d, the heat medium outlet 3e, etc. In addition, the number of baffles can be increased or decreased. When increasing the number of baffle plates, it is advantageous in terms of heat exchange efficiency to make the heat medium A meander by arranging a plurality of baffle plates alternately as in the above-mentioned baffle plates 7a and 7b. ..

The second shell 5 has substantially the same structure as the first shell 3, and is a hollow member having a cylindrical shape as a whole. The lower surface of the side surface 5a forming a cylindrical surface is covered with the bottom plate 5b, and the upper surface is covered with the upper plate 5c, and the pipe 4 constituting the second heating line extends from the bottom plate 5b to the upper plate 5c. The bottom plate 5b and the top plate 5c are penetrated through the end of the pipe 4, and the space inside the pipe 4 and the space inside the second shell 5 and outside the pipe 4 are isolated from each other. A heat medium inlet 5d is provided at one location near the upper end of the side surface 5a, and a heat medium outlet 5e is provided at a location near the lower end on the side opposite to the heat medium inlet 5d with respect to the central axis of the side surface 5a. The heat medium A is circulated inside and outside the tube 4. In the example shown here, the second shell 5 does not have a configuration corresponding to the baffle plates 7a and 7b in the first shell 3, but it depends on the dimensions of the second shell 5 and the required heat exchange amount. May be provided with a baffle plate similar to the baffle plates 7a and 7b as appropriate.

In the case of the first embodiment, the number of the pipes 2 and the pipes 4 housed in the first shell 3 and the second shell 5 are different from each other, and the first shell 3 is used for the first heating. The number of pipes 2 forming the line is set to be larger than the number of pipes 4 forming the second heating line in the second shell 5. Along with this, the diameter of the first shell 3 is set to be larger than the diameter of the second shell 5. Note that FIG. 1 is a schematic diagram for conceptually explaining the configuration of the heat exchanger 1, and the diameters and numbers of the pipes 2 and 4 shown in FIG. 1 do not necessarily reflect the actual situation as they are. The same applies to FIGS. 2 to 5 below.

In the first embodiment, the material, diameter, and wall thickness of each pipe 2 are the same as the material, diameter, and wall thickness of each pipe 4, and therefore, it relates to heat exchange per unit length of one pipe. Performance is equal between tube 2 and tube 4. However, since the number of pipes 2 is larger than the number of pipes 4, the flow path cross-sectional area of the first heating line as a whole is larger than the flow path cross-sectional area of the second heating line as a whole. Therefore, if the fluid L to be heated is circulated at the same speed and at the same density, the amount of the fluid L to be heated flowing per unit length of the entire pipe 2 constituting the first heating line is the same as that of the second heating line. It is larger than the amount of the fluid L to be heated that flows per unit length of the entire constituent pipe 4. Further, if the heated fluid L is circulated in the same amount, the flow velocity of the heated fluid L flowing through the pipe 2 becomes slower than the flow velocity of the heated fluid L flowing through the pipe 4.

The intermediate shell 6 is a hollow member installed between the lower first shell 3 and the upper second shell 5. The side surface 6a of the intermediate shell 6 forms a conical surface of a conical surface as a whole, and the lower diameter of the conical surface is the diameter of the upper plate 3c of the first shell 3, and the upper diameter is the diameter of the second shell. It is equal to the diameter of the bottom plate 5b of 5. The lower and upper ends of the side surface 6a are circumferentially welded to the upper end of the side surface 3a of the first shell 3 and the lower end of the side surface 5a of the second shell 5, respectively, and the side surface 6a of the intermediate shell 6 and the upper plate of the first shell 3 are welded. A truncated cone-shaped space is formed by 3c and the bottom plate 5b of the second shell 5. This space communicates with the space inside the pipe 2 forming the first heating line and the space inside the pipe 4 forming the second heating line, and is connected to the space outside the pipe 2 and inside the first shell 3 and the space inside the first shell 3. The space outside the tube 4 and inside the second shell 5 is separated from the space inside the second shell 5 by the upper plate 3c of the first shell 3 and the bottom plate 5b of the second shell 5, respectively. In this way, the intermediate shell 6 forms a flow path of the fluid L to be heated that connects the first heating line formed by the tube 2 and the second heating line formed by the tube 4.

An anterior chamber 8 is provided below the first shell 3 so as to cover the lower side of the bottom plate 3b, and the heated fluid L is provided in the anterior chamber 8 from the heated fluid inlet 8a to the inside of the anterior chamber 8. It is supplied to the space and introduced from here to the tube 2 which is the first heating line. A rear chamber 9 is provided above the second shell 5 so as to cover the upper side of the upper plate 5c, and the fluid L to be heated flowing through the pipe 4 which is the second heating line is the rear chamber 9. After being guided to the internal space, it flows out downstream from the heated fluid outlet 9a provided in the rear chamber 9.

In this way, in the heat exchanger 1 of the first embodiment, the heated fluid L is introduced into the anterior chamber 8 from the heated fluid inlet 8a at the lower part of the heat exchanger 1 and flows into the pipe 2 from below. After exchanging heat with the heat medium A in the shell 3, it is extracted into the upper intermediate shell 6 and further flowed from the intermediate shell 6 below the tube 4 to exchange heat with the heat medium A in the second shell 5. It is drawn out from the rear chamber 9 through the upper heated fluid outlet 9a.

At this time, as described above, the number of tubes 2 constituting the first heating line is larger than the number of tubes 4 constituting the second heating line. Therefore, the contact area of the fluid L to be heated with the heat medium A per volume is larger in the tube 2 than in the tube 4. Further, in the pipe 2, since the total flow path cross-sectional area of the fluid L to be heated is larger than that of the pipe 4 due to the large number of pipes 2, the flow velocity of the fluid L to be heated is slow. Therefore, the fluid L to be heated is heated while slowly flowing through the pipe 2, so that the amount of heat exchange per unit length becomes large. As a result, the performance related to heat exchange in the first shell 3 is higher than that in the second shell 5.

As described above, in the first shell 3, the fluid L to be heated that flows in as a low-temperature liquid is mainly vaporized, and a large amount of heat of vaporization is taken from the heat medium A, so that a large amount of heat exchange is required. If the contact area between the heated fluid L and the heat medium A is large and the flow velocity of the heated fluid L is small, more heat can be transferred from the heat medium A to the heated fluid L. The fluid L to be heated is efficiently vaporized in one shell 3.

Further, at this time, in the first shell 3, the distance between the pipes 2 is wider than the distance between the pipes 4. Further, since the area of the cross section orthogonal to the tube 2 of the first shell 3 is larger than the area of the cross section orthogonal to the tube 4 of the second shell 5, the capacity of the heat medium A in the first shell 3 is large. It is secured sufficiently large with respect to the volume of the fluid L to be heated flowing through the pipe 2. Therefore, it is possible to prevent a situation in which the heat medium A, which has been deprived of a large amount of heat due to the vaporization of the fluid L to be heated, freezes.

On the other hand, in the second shell 5, the heated fluid L vaporized in the first shell 3 flows, and here only the heated fluid L is overheated, so that the required heat exchange efficiency is small. .. Therefore, even if the contact area of the fluid L to be heated with the heat medium A is smaller than that of the first shell 3 and the flow velocity is high, there is no problem in performance.

As described above, in the heat exchanger 1 of the first embodiment, the shell, which was conventionally one-stage, is divided into two stages, the first shell 3 and the second shell 5, so that the shell can be connected to the upstream side of the heat exchanger 1. The flow path configuration can be changed on the downstream side to make the performance related to heat exchange different. Therefore, the first shell 3 and the second shell 5 are each designed according to the performance required for heat exchange, and the performance of each part of the heat exchanger 1 is optimized so as to meet the performance required for each part. It is possible. In the conventional heat exchanger, the flow path on the downstream side where the performance related to heat exchange is excessive can be made into a structure that matches the performance originally required, and as a result, the flow path for the excess performance can be obtained. It is possible to reduce the number of configurations related to the above, and it is possible to suppress the increase in size of the device. At this time, since the intermediate shell 6 is interposed between the first shell 3 and the second shell 5 as a flow path for the fluid L to be heated, a pipe is provided between the first shell 3 and the second shell 5. Even if the flow path configurations of 2 and 4 are different, no inconvenience occurs with respect to the flow of the fluid L to be heated.

Further, at this time, the fluid L to be heated that has passed through each of the pipes 2 is extracted into the intermediate shell 6 and then introduced into the downstream pipe 4, so that the fluids L are mixed once when they flow into the intermediate shell 6 and then the pipes. It will flow into 4. Therefore, even if there is a variation in the temperature of the heated fluid L at the outlet of the pipe 2 between the pipes 2, as a result of mixing the heated fluid L extracted from each pipe 2 in the intermediate shell 6, later The effect of homogenizing the temperature of the fluid L to be heated extracted from above the pipe 4 can also be expected.

Here, FIG. 1 illustrates a case where a structure or the like is not particularly provided inside the intermediate shell 6, but for example, a straightening vane that guides the flow of the fluid L to be heated or the intermediate shell 6 is provided in this portion. A structural material or the like for ensuring strength may be separately provided.

Further, with respect to the tubes 2 and 4, the length of the flow path in contact with the heat medium A is adjusted by appropriately changing the length of each, and thus the amount of heat exchange in each of the first shell 3 and the second shell 5 is increased. Can be adjusted. That is, the length of the pipe 2 is the length of the flow path that can appropriately vaporize the fluid L to be heated, and the length of the pipe 4 is the length of the flow path that can superheat the vaporized fluid L to the required temperature. Each may be set appropriately at the design stage.

In the first shell 3 and the second shell 5, as described above, the heat medium A flows from the heat medium inlets 3d and 5d provided near the upper end to the heat medium outlets 3e and 5e provided near the lower end, respectively. It has become. On the other hand, since the fluid L to be heated flowing through the pipes 2 and 4 flows from the bottom to the top, the flow of the fluid L to be heated and the flow of the heat medium A are countercurrents facing each other vertically as a whole. For the heat medium A, heat is gradually taken away from the upper side to the lower side of the first shell 3 or the second shell 5, and the temperature gradually decreases, and for the fluid to be heated L, the temperature is higher from the lower side to the upper side. Since the heat is received in contact with the high heat medium A one after another, efficient heat exchange is possible.

The structure in which the shell is divided in this way also has advantages in terms of strength and durability. In the conventional heat exchanger, since each pipe constituting the flow path is a single long pipe from the upstream to the downstream, the rigidity is reduced, and there is a tendency that twisting, vibration, deformation due to them, etc. are likely to occur. rice field. In the case of the heat exchanger 1 of the first embodiment, the pipes 2 and 4 constituting the first heating line and the second heating line are each shell (first shell 3, second shell) having a divided length. Since it is equal to the length of the shell 5), the total length is significantly shorter than that of the conventional one-stage shell heat exchanger. Therefore, the rigidity of each of the pipes 2 and 4 can be easily maintained, and problems such as vibration and deformation can be easily avoided.

Here, in the first embodiment described above, a two-stage heat exchange in which one intermediate shell 6 is provided between two shells (first shell 3, second shell 5) accommodating pipes 2 and 4. Although the vessel 1 has been illustrated, the configuration of the present invention is not limited to this. For example, a total of three shells accommodating pipes can be used, and a three-stage heat exchanger having two intermediate shells between the three shells can be used, or the number of stages can be further increased. It doesn't matter. In addition, the number of shells per heat exchanger can be changed as appropriate. This also applies to the second to fourth embodiments described later.

As described above, in the heat exchanger 1 of the first embodiment, the first shell 3 accommodating the first heating line 2 and the second heating line 4 located downstream of the first heating line 2 are provided. The housed second shell and an intermediate shell 6 located between the first shell 3 and the second shell 5 and configured to allow the fluid L to be heated to flow through the space provided inside are provided. At least one of the cross-sectional area of the flow path of the fluid L to be heated in one shell 3, the contact area with the heat medium A per volume of the fluid L to be heated, or the capacity of the heat medium A per volume of the fluid L to be heated. Since it is configured to be larger than the second shell 5, the performance related to heat exchange in the first shell 3 can be made different from that of the second shell 5.

In the heat exchanger 1 of the present invention, the first heating line 2 is configured as a plurality of tubes 2, the second heating line 4 is configured as one or more tubes 4, and the number of tubes 2 is the number of tubes 4. Since the number is larger than the number, the contact area between the flow path cross-sectional area of the fluid L to be heated in the first shell 3 and the heat medium A per volume of the fluid L to be heated in the first shell 3 is made larger than that in the second shell 5 by a simple configuration. be able to.

In the heat exchanger 1 of the present invention, the distance between the pipes 2 is set wider than the distance between the pipes 4, and the area of the cross section orthogonal to the pipe of the first shell is orthogonal to the pipe of the second shell. Since the area is set to be larger than the area of, the capacity of the heat medium A per volume of the fluid to be heated L in the first shell 3 can be made larger than that in the second shell 5 by a simple configuration.

The heat exchanger 1 of the present invention draws the heated fluid L introduced into the first heating line 2 from the lower part of the first shell 3 to the upper part of the second heating line 4 via the intermediate shell 6. Since it is configured, the performance related to heat exchange can be optimized for each part of the heat exchanger 1 of the type that extracts the heated fluid L introduced from below upward.

Therefore, according to the heat exchanger of the first embodiment, the performance related to heat exchange can be optimized for each part, and the size of the apparatus can be suppressed.

FIG. 2 shows the form of the heat exchanger according to the second embodiment of the present invention. The basic configuration is the same as that of the heat exchanger 1 (see FIG. 1) of the first embodiment, but in the case of the heat exchanger 21 of the second embodiment, the first shell 23 on the upstream side and the first shell 23 on the downstream side are on the downstream side. The performance related to heat exchange is optimized by making the diameter and arrangement of the second shell 25 different from that of the second shell 25, not the number of pipes 22 and 24.

Specifically, the pipe 22 constituting the first heating line on the upstream side has a larger diameter than the pipe 24 forming the second heating line on the downstream side. In this way, the contact area of the heated fluid L with the heat medium A per volume in the pipe 22 is smaller than that of the pipe 24, but the flow velocity of the heated fluid L in the pipe 22 is smaller than the flow velocity in the pipe 24. If the flow velocity is sufficiently small, the amount of heat exchange per unit length can be increased. Therefore, the performance related to heat exchange required in the first shell 23 on the upstream side where the fluid to be heated L is vaporized can be obtained. It can be secured sufficiently. Further, at this time, by widening the distance between the pipes 22 constituting the first heating line and increasing the cross-sectional area of the first shell 23, a sufficient amount of heat medium A for heat exchange is provided to the pipes 22. It can be circulated in between to prevent the heat medium A from freezing. On the other hand, in the second shell 25 that overheats the vaporized fluid L to be heated, the performance of the first shell 23 is not required for heat exchange, and there is no possibility that the heat medium A freezes, so that the diameter of the tube 24 is reduced. Therefore, there is no particular problem even if the flow velocity of the fluid L to be heated is increased, the distance between the pipes 24 is narrowed, and the cross-sectional area of the second shell 25 is reduced.

Since other configurations and operational effects are the same as those of the heat exchanger of the first embodiment, the description thereof will be omitted. However, the heat exchanger of the second embodiment also has the performance related to heat exchange for each part. It can be optimized and the size of the device can be suppressed.

FIG. 3 shows the form of the heat exchanger according to the third embodiment of the present invention. The basic configuration is the same as that of the heat exchanger 1 (see FIG. 1) and the heat exchanger 21 (see FIG. 2) of the first and second embodiments, but the heat exchanger 31 of the third embodiment. In this case, the number of pipes 32 of the first shell 33 on the upstream side is larger than the number of pipes 34 of the second shell 35 on the downstream side, and the diameter of each pipe 32 is smaller than the diameter of each pipe 34. As a result, in the pipe 32 constituting the first heating line, the contact area with the heat medium A per volume of the fluid L to be heated is larger than that of the pipe 34 forming the second heating line. The total flow path cross-sectional area of the fluid L to be heated in the pipe 32 is equal to the total flow path cross-sectional area in the pipe 34.

In this way, the flow velocity of the fluid to be heated L does not differ so much between the pipe 32 and the pipe 34 (however, since the vaporized fluid L to be heated flows through the pipe 34, the liquid is contained in the pipe 32. The flow velocity is faster than that of the fluid L to be heated that flows in the phase state), but high heat exchange efficiency is ensured in the tube 32 due to the large contact area with the heat medium A.

Here, in the third embodiment, the contact area between the fluid L to be heated and the heat medium A in the first heating line 32 is increased by installing more pipes 32 than the pipes 34, but the contact area is adjusted. Is not limited to changing the number of pipes, but can also be changed, for example, by changing the shape of the pipe 32. For example, if the pipe 32 is a flat pipe and the pipe 34 is a circular pipe, even if the total flow path cross-sectional area is the same between the pipe 32 and the pipe 34, the fluid L to be heated and the heat medium A in the pipe 32 The contact area with is larger than that of the pipe 34.

Since other configurations and operational effects are the same as those of the heat exchanger of the first embodiment, the description thereof will be omitted. However, the heat exchanger of the third embodiment also has the performance related to heat exchange for each part. It can be optimized and the size of the device can be suppressed.

FIG. 4 shows the form of the heat exchanger according to the fourth embodiment of the present invention, and the basic configuration is the heat exchangers 1, 21, 31 of the first to third embodiments (see FIGS. 1 to 3). Is similar to. In the heat exchanger 41 of the fourth embodiment, the number of pipes 42 of the first shell 43 on the upstream side is the same as the number of pipes 44 of the second shell 45 on the downstream side, and each pipe 42 and each The diameter of the pipe 44 is also the same. That is, there is no difference in the contact area of the heated fluid L with the heat medium A per volume between the pipe 42 and the pipe 44, and the flow velocity of the heated fluid L is also the flow velocity of the liquid phase and the gas phase. There is no greater difference than the difference in flow velocity. However, in the first shell 43, the distance between the pipes 42 is wider than the distance between the pipes 44 in the second shell 45, so that a larger amount of heat medium A circulates between the pipes 42. There is. Further, the area of the cross section of the first shell 43 orthogonal to the pipe 42 is larger than the area of the cross section orthogonal to the pipe 44 of the second shell 45, and the capacity of the heat medium A in the first shell 43 is larger than that of the second shell 45. Is also getting bigger.

In this way, in the first shell 43, the capacity of the heat medium A that exchanges heat with the heated fluid L is sufficiently large with respect to the volume of the heated fluid L flowing through the pipe 42. Therefore, in the first shell 43 in which the fluid L to be heated is vaporized, the amount of heat exchange between the fluid L to be heated and the heat medium A can be increased, and the heat medium A can be prevented from freezing.

Since other configurations and operational effects are the same as those of the heat exchanger of the first embodiment, the description thereof will be omitted. However, the heat exchanger of the fourth embodiment also has the performance related to heat exchange for each part. It can be optimized and the size of the device can be suppressed.

FIG. 5 shows an example of a heat exchange system to which the heat exchanger of the present invention is applied as described above. Here, as the heat exchanger, the case where the same heat exchanger 1 as in the first embodiment (see FIG. 1) is adopted is illustrated.

In this heat exchange system, the shell of the heat exchanger 1 is divided into two stages, an upstream side and a downstream side, and heat is supplied to the first shell 3 on the upstream side and the second shell 5 on the downstream side. The flow rate of the medium A can be adjusted individually.

The pump 10 pumps seawater as the heat medium A and sends it to the first shell 3 and the second shell 5 via the heat medium supply flow path 11. The heat medium supply flow path 11 is branched into a first branch path 11a and a second branch path 11b downstream of the pump 10, and the first branch path 11a is at the heat medium inlet 3d of the first shell 3 and is second. The branch path 11b is connected to the heat medium inlet 5d of the second shell 5, respectively. A first heat medium flow valve 12 and a second heat medium flow valve 13 are provided in the middle of the first branch path 11a and the second branch path 11b, respectively, from which the pump 10 to the first shell 3 or the second. The amount of heat medium A sent to the shell 5 can be adjusted. The heat medium A sent from the heat medium inlets 3d and 5d to the first shell 3 and the second shell 5 is discharged from the heat medium outlet 3e or the heat medium outlet 5e, respectively. Here, the case where seawater is circulated as the heat medium A is illustrated, but in addition to this, a method of circulating a heat medium such as antifreeze while heating it may be adopted.

The output of the pump 10 is controlled by the flow rate control signal 10a input from the control device 14 to the pump 10, whereby the flow rate of the heat medium A sent to the heat medium supply flow path 11 is manipulated. The control device 14 is a control device that controls the entire heat exchange system using the heat exchanger 1, and also indicates the opening degree of the first heat medium flow valve 12 and the second heat medium flow valve 13, respectively. It is designed to be controlled via 12a and 13a.

The intermediate shell 6 of the heat exchanger 1 is provided with a temperature sensor 15 and a pressure sensor 16, and the temperature sensor 15 and the pressure sensor 16 detect the temperature and pressure of the fluid L to be heated in the intermediate shell 6. The temperature signal 15a and the pressure signal 16a are input to the control device 14, respectively.

The heated fluid L is supplied from the tank 17 to the heated fluid inlet 8a provided in the front chamber 8 below the heat exchanger 1 via the heated fluid supply flow path 18. A fluid to be heated flow valve 19 is provided in the middle of the fluid supply flow path 18 to be heated, and the fluid to be heated to be supplied to the heat exchanger 1 by changing the opening degree of the fluid flow valve 19 to be heated. The amount of L can be adjusted. The opening degree of the fluid flow rate valve 19 to be heated is operated by the opening degree signal 19a input from the control device 14.

With the above configuration, in the control device 14, based on the detected values of the temperature and pressure of the fluid L to be heated in the intermediate shell 6, the supply amount of the fluid L to be heated to the heat exchanger 1 and the first shell 3 and the second shell 3 are used. The amount of heat medium A supplied to the shell 5 can be adjusted as appropriate. Since the temperature of the heat medium A fluctuates depending on various conditions such as climate, the state of the fluid L to be heated is constantly monitored by the intermediate shell 6, and for example, when the temperature of the fluid L to be heated is low, a pump is used. The amount of heat medium A supplied from 10 is increased and the opening degree of the second heat medium flow valve 13 is increased to increase the amount of heat medium A supplied to the second shell 5, and the heat in the second shell 5 is increased. The amount of exchange is increased to increase the amount of overheating of the fluid L to be heated. Further, for example, if the pressure of the fluid L to be heated in the intermediate shell 6 is low, the supply amount of the heat medium A from the pump 10 is increased and the opening degree of the first heat medium flow valve 12 is increased. The amount of heat medium A supplied to the shell 3 is increased, and the amount of heat exchange in the first shell 3 is increased to promote the vaporization of the fluid L to be heated. Alternatively, the opening degree of the fluid to be heated flow valve 19 can be increased to increase the supply amount of the fluid to be heated L. In addition, the control device 14 can perform various adjustments regarding the supply amount of the heated fluid L and the heat medium A depending on the detected temperature and pressure of the heated fluid L. Although the case where the temperature sensor 15 and the pressure sensor 16 are provided as the sensors for monitoring the state of the fluid L to be heated is illustrated here, only one of the temperature sensor 15 and the pressure sensor 16 is provided. It is also possible to control the supply amount of the fluid L to be heated and the heat medium A.

At this time, in the heat exchange system of this embodiment, the heat medium A is mainly supplied to the first shell 3 where the heated fluid L is vaporized, and the second shell 5 where the heated fluid L is overheated is supplied. Since the supply of the heat medium A is controlled separately, it is possible to control the amount of vaporization and the amount of superheat individually. Therefore, the operation for keeping the amount and temperature of the heated fluid L finally discharged from the heated fluid outlet 9a in a required state is easy.

Further, in grasping the state of the fluid L to be heated in the heat exchanger 1, the installation location of the temperature sensor 15 and the pressure sensor 16 is intermediate between the first shell 3 where vaporization is performed and the second shell 5 where overheating is performed. The intermediate shell 6 corresponding to the point is used. Since the state of the fluid to be heated L is monitored at a point on the way from vaporization to overheating, the cover in the heat exchanger 1 is compared with the case where the temperature sensor 15 and the pressure sensor 16 are attached to the front chamber 8 and the rear chamber 9, for example. It is possible to appropriately grasp the heating state of the heating fluid L.

As described above, in the heat exchange system of the present embodiment, since the heat exchanger 1 includes at least one of the temperature sensor 15 and the pressure sensor 16, the amount of vaporization of the fluid L to be heated by the heat exchanger 1 The amount of superheat can be individually manipulated, and the operation can be facilitated in maintaining the amount and temperature of the finally discharged fluid L to be heated in a required state.

In the heat exchange system of the present invention, since the temperature sensor 15 or the pressure sensor 16 is provided in the intermediate shell 6, the heating state of the fluid L to be heated in the heat exchanger 1 can be appropriately grasped. ..

Other configurations and effects are the same as those of the heat exchanger of the first embodiment adopted in the system, and thus description thereof will be omitted. However, according to the heat exchange system of the present embodiment. , The performance related to heat exchange can be optimized for each part, and the size of the device can be suppressed.

The heat exchanger and heat exchange system of the present invention are not limited to the above-described embodiment, and various fluids other than LNG can be assumed as the fluid to be heated. Of course, various changes can be made within the range that does not deviate from.

1 Heat exchanger 2 First heating line (tube)
3 1st shell 4 2nd heating line (tube)
5 Second shell 6 Intermediate shell 15 Temperature sensor 16 Pressure sensor 21 Heat exchanger 22 First heating line (tube)
23 1st shell 24 2nd heating line (tube)
25 Second shell 31 Heat exchanger 32 First heating line (tube)
33 1st shell 34 2nd heating line (tube)
35 Second shell 41 Heat exchanger 42 First heating line (tube)
43 1st shell 44 2nd heating line (tube)
45 Second shell A Heat medium L Fluid to be heated

Claims (5)

A first shell configured to house a first heating line through which a fluid to be heated flows and to supply a heat medium around the first heating line.
A second shell configured to house a second heating line for circulating a fluid to be heated that has passed through the first heating line and to supply a heat medium around the second heating line.
An intermediate shell located between the first shell and the second shell and configured to allow a fluid to be heated to flow in a space provided inside is provided.
The fluid to be heated introduced into the first heating line from the lower part of the first shell is configured to be withdrawn above the second heating line via the intermediate shell.
The flow path cross-sectional area of the fluid to be heated in the first shell and the heat to be heated so that the amount of heat exchanged per unit length in the first heating line is larger than the amount of heat exchanged per unit length in the second heating line. A shell-and-tube type heat exchange configured such that at least one of the contact area with the heat medium per volume of the fluid or the capacity of the heat medium per volume of the fluid to be heated is larger than that of the second shell. vessel. The first heating line is configured as a plurality of tubes, the second heating line is configured as one or more tubes, and the number of tubes constituting the first heating line constitutes the second heating line. The heat exchanger according to claim 1, which is larger than the number of heat exchangers. The first heating line and the second heating line are each configured as a plurality of pipes, and the distance between the pipes constituting the first heating line is set wider than the distance between the pipes constituting the second heating line. The heat exchanger according to claim 1, wherein the area of the cross section orthogonal to the tube of the first shell is set to be larger than the area of the cross section orthogonal to the tube of the second shell. The heat exchange system using the heat exchanger according to claim 1, wherein the heat exchanger includes at least one of a temperature sensor for detecting the temperature of the fluid to be heated and a pressure sensor for detecting the pressure of the fluid to be heated. The heat exchange system according to claim 4 , wherein the temperature sensor or the pressure sensor is provided in the intermediate shell.

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