JP6864988B2 - Heat exchanger - Google Patents

Description

The techniques disclosed herein relate to heat exchangers.

Patent Document 1 describes an underwater combustion type vaporizer (Submerged Combustion Vaporizer) as one of the heat exchange devices for raising the temperature of a fluid such as a low temperature liquefied gas. The underwater combustion type vaporizer is a device for vaporizing liquefied natural gas, and is a plurality of spurge pipes that are immersed in a water tank and eject combustion gas from a burner into water through bubble ejection holes formed on the peripheral surface. And a heat exchanger having a heat transfer tube immersed in a water tank and arranged above the spurge pipe. The combustion gas ejected as bubbles into the water heats the low-temperature liquefied gas flowing in the heat transfer tube while stirring the water in the water tank. This vaporizes the cryogenic liquefied gas.

Further, as in the case of the underwater combustion type vaporizer, a high temperature gas is ejected as bubbles from a spurge pipe arranged in the water tank, so that the gas is immersed in the water tank and flows in a heat transfer tube arranged above the spurge pipe. As a vaporizer for vaporizing the liquefied gas, an intermediate heat medium type vaporizer such as a steam ejector type vaporizer is also known.

Furthermore, there is also a heat exchange device configured to raise the temperature of natural gas or the like flowing in the heat transfer tube of the heat exchanger immersed in the water tank by ejecting high-temperature gas as bubbles from a spurge pipe arranged in the water tank. Are known.

JP-A-2015-55269

In the heat exchange device including the above-mentioned underwater combustion type vaporizer, intermediate heat medium type vaporizer, and the like, the heat transfer tube immersed in the water tank is supported by the support member. As shown in FIG. 2 of Patent Document 1, the support member is a plate-shaped member that spreads so as to be orthogonal to the tube axis of the heat transfer tube, and is not specified in Patent Document 1, but is in the thickness direction. It has a support hole that penetrates through. The heat transfer tube is supported by the support member by being inserted into the support hole so as to penetrate the support member. The support member is made of a synthetic resin such as a phenolic resin.

The inventors of the present application have found that corrosion of a heat transfer tube made of stainless steel can occur in a heat exchange device having such a configuration.

The technique disclosed herein has been made in view of this point, and an object thereof is to prevent corrosion of the heat transfer tube in a heat exchange device having a heat transfer tube immersed in a water tank.

When the inventors of the present application examined the corrosion of the heat transfer tube in the heat exchange device, it was found that this corrosion was the crevice corrosion at the place where the support member supports the heat transfer tube.

That is, the water stored in the aquarium is generally industrial water and has a relatively high concentration of chloride ions. On the other hand, in the support portion of the support member, a gap is formed at a portion where the outer peripheral surface of the stainless steel heat transfer tube and the inner peripheral surface of the support hole made of synthetic resin are in contact with each other. As a result of the concentration of chloride ions inside the gap, the passivation film of the heat transfer tube is destroyed and the heat transfer tube is locally corroded.

Here, when a heat exchange device such as an underwater combustion type vaporizer or an intermediate heat medium type vaporizer is operated, the water in the water tank flows violently, so that the concentration of chloride ions in the gap is suppressed. That is, corrosion of the heat transfer tube is prevented. However, underwater combustion type vaporizers, intermediate heat medium type vaporizers, etc. may also be used for peak shaving and emergency to cover a rapid increase in demand, in which case, for a long period of time. It may not be driven. If the water in the water tank remains stagnant without being operated for a long period of time, crevice corrosion of the heat transfer tube is likely to occur.

Corrosion of the heat transfer tube occurs where the support member supports the heat transfer tube. Therefore, when the heat exchange device is not operated for a long period of time, the position of the support member in the water tank may be shifted regularly. Conceivable. For example, by shifting the arrangement position of the support member and periodically changing the contact point between the heat transfer tube and the support hole, it is possible to suppress the interstitial corrosion of the heat transfer tube. However, this measure has the disadvantage that maintenance becomes complicated.

Therefore, the inventors of the present application have decided to prevent corrosion of the heat transfer tube by making the contact area between the heat transfer tube and the support hole as small as possible.

Heat exchanger you disclosed herein, and is immersed in the water tank has a Supajipaipu configured to jet a high-temperature gas in water, the heat transfer tubes disposed on the upper side of the Supajipaipu in the water tank and A heat exchanger configured to raise the temperature of the fluid flowing inside the heat transfer tube by stirring and heating water by bubbles ejected from the spurge pipe, and the heat transfer tube immersed in the water tank. It comprises a support member configured to support it.

The support member is a plate-shaped member that extends so as to be orthogonal to the tube axis of the heat transfer tube, and has a support hole through which the heat transfer tube penetrates. is tapered in the thickness direction of the member, the smallest diameter of the support hole is larger than the outer diameter of the heat transfer tubes, the heat transfer tube, the minimum diameter of the edge-shaped portions of said support hole, the point It is supported by contact so as to make contact or line contact.

According to this configuration, since the inner peripheral surface of the support hole is tapered in the thickness direction of the support member, the outer peripheral surface of the heat transfer tube inserted into the support hole is only at the portion having the smallest diameter in the support hole. , Contact the inner peripheral surface of the support hole. Since the contact point between the inner peripheral surface of the support hole and the outer peripheral surface of the heat transfer tube does not widen in the thickness direction of the support member, the contact area between the inner peripheral surface of the support hole and the outer peripheral surface of the heat transfer tube becomes smaller. As a result, it becomes possible to suppress crevice corrosion at the contact points between the inner peripheral surface of the support hole and the outer peripheral surface of the heat transfer tube.

The minimum diameter of the support hole, than the outer diameter of the heat transfer tube Ri Oh large, the heat transfer tube, since that will be supported in contact with the minimum diameter of the edge-shaped portions of said support hole, the outer periphery of the heat transfer tube The surface makes point contact or line contact with the inner peripheral surface of the support hole. Since the contact area between the two is small, it is possible to suppress crevice corrosion at the contact point between the inner peripheral surface of the support hole and the outer peripheral surface of the heat transfer tube.

Here, "point contact" means a contact state in which the contact area is very small and the contact portion between the inner peripheral surface of the support hole and the outer peripheral surface of the heat transfer tube can be regarded as a substantially point. However, it is different from the "point" in the mathematical sense. Further, "line contact" also means a contact state in which the contact width is very small and the contact portion between the inner peripheral surface of the support hole and the outer peripheral surface of the heat transfer tube can be regarded as a line substantially. , Different from "line" in the mathematical sense. Further, "line contact" means that the contact portion between the inner peripheral surface of the support hole and the outer peripheral surface of the heat transfer tube has a certain length in the circumferential direction of the heat transfer tube or the tube axis direction. It is different from "point contact".

For example, when the heat transfer tube is a circular tube, if the support hole of the support member has a circular cross section, the outer peripheral surfaces of the heat transfer tube come into contact with each other at a point having the smallest diameter in the support hole. The contact area between the inner peripheral surface of the support hole and the outer peripheral surface of the heat transfer tube becomes smaller, and it becomes possible to suppress crevice corrosion at the contact point between the inner peripheral surface of the support hole and the outer peripheral surface of the heat transfer tube. .. Further, when the heat transfer tube is a circular tube, if the support hole of the support member has a circular cross-sectional shape, the contact point between the two is the lowest position of the heat transfer tube and the lowest position of the support hole. Here, even if the position of the heat transfer tube shifts and the contact point between the inner peripheral surface of the support hole and the outer peripheral surface of the heat transfer tube changes, both the inner peripheral surface of the support hole and the outer peripheral surface of the heat transfer tube have a circular shape. If so, they will always come into contact at one point. With this configuration, the contact area between the inner peripheral surface of the support hole and the outer peripheral surface of the heat transfer tube can always be kept small.

On the inner peripheral surface of the support hole, a plurality of concave grooves extending in a direction along the tube axis of the heat transfer tube may be formed in a striped pattern.

By doing so, at the contact point between the inner peripheral surface of the support hole and the outer peripheral surface of the heat transfer tube, that is, the part having the minimum diameter of the support hole, the inner peripheral surface of the support hole and the heat transfer tube are formed by the amount of the concave groove. The contact area with the outer peripheral surface becomes smaller. Gap corrosion at the contact points between the inner peripheral surface of the support hole and the outer peripheral surface of the heat transfer tube can be further suppressed.

A grid-like recess may be formed on the inner peripheral surface of the support hole. By doing so, at the contact point between the inner peripheral surface of the support hole and the outer peripheral surface of the heat transfer tube, the contact area between the inner peripheral surface of the support hole and the outer peripheral surface of the heat transfer tube is reduced by the amount of the recess. Gap corrosion at the contact points between the inner peripheral surface of the support hole and the outer peripheral surface of the heat transfer tube can be further suppressed.

As described above, according to the heat exchange device, the contact area between the outer peripheral surface of the heat transfer tube inserted into the support hole and the inner peripheral surface of the support hole becomes smaller, so that the contact area with the inner peripheral surface of the support hole becomes smaller. , Gap corrosion at the contact point with the outer peripheral surface of the heat transfer tube can be suppressed.

FIG. 1 is a conceptual diagram showing the overall configuration of an underwater combustion type vaporizer. FIG. 2 is a front view showing a heat exchanger and a spurge pipe arranged in a water tank. FIG. 3 is a plan view of the heat exchanger shown in FIG. 2 and the spurge pipe. FIG. 4 is an enlarged side view showing a part of the support member. FIG. 5 is a diagram showing a VV cross section of FIG. FIG. 6 is an enlarged side view showing a portion of the support hole. FIG. 7 is a diagram showing a cross section of VII-VII of FIG. 8 (a) to 8 (c) are views showing a modified example of the support hole. FIG. 9 is a view corresponding to FIG. 6 showing a support hole having a rectangular cross section. FIG. 10 is a diagram showing a modified example of the support hole. FIG. 11 is a diagram corresponding to FIG. 6 showing a support hole having a diamond-shaped cross section. 12 (a) to 12 (c) are views showing a modified example of the support hole. FIG. 13 is a diagram illustrating a concave groove formed on the inner peripheral surface of the support hole. FIG. 14 is a diagram illustrating a grid-like recess formed on the inner peripheral surface of the support hole. FIG. 15 is a diagram corresponding to FIG. 6 showing a modified example of the support hole.

Hereinafter, embodiments of the heat exchange apparatus will be described with reference to the drawings. FIG. 1 schematically shows the entire underwater combustion type vaporizer 1 as one of the heat exchange devices. 2 and 3, respectively, show the configuration of the support member 4 that supports the heat exchanger 32, the spurge pipe 15, and the heat transfer tube 31 immersed in the water tank 11. The underwater combustion type vaporizer 1 is one of the vaporizers for the low temperature liquefied gas, and here, the liquefied natural gas (LNG) is vaporized.

The underwater combustion type vaporizer 1 includes, for example, a heat exchanger 32 that is immersed in a rectangular parallelepiped water tank 11 and has a large number of heat transfer tubes 31 that serve as LNG flow paths bent and molded in multiple stages. .. One end of each heat transfer tube 31 communicates with the LNG inlet tube 12b, which is the inlet of LNG, and the other end communicates with the NG outlet tube 12c, which is the outlet of vaporized natural gas (NG). In FIG. 1, the heat transfer tube 31 is shown in a simplified manner, but in reality, as shown in FIGS. 2 and 3, the heat transfer tube 31 extending in the X direction and being bent and formed in multiple stages in the Z direction is actually formed. , A large number of heat transfer tubes 31 are arranged side by side in the Y direction, and each heat transfer tube 31 communicates with the LNG inlet header 33 connected to the LNG inlet tube 12b and the NG outlet header 34 connected to the NG outlet tube 12c. doing. The number, number, and arrangement of bending steps of the heat transfer tube 31 are appropriately determined according to the performance of the underwater combustion type vaporizer 1.

The water tank 11 is covered with, for example, a rectangular plate-shaped top plate 11a. The top plate 11a is arranged so that a worker can walk and a cylindrical downcomer 13 is immersed in the water tank 11 at a predetermined position thereof.

At the upper end of the downcomer 13, a burner 2 for burning the fuel gas supplied from the fuel supply source (not shown) via the fuel supply pipe 6 and the air supplied through the blower 14 is provided.

At the bottom of the water tank 11, a spurge pipe 15 is arranged, which communicates with the downcomer 13 and has a large number of bubble ejection holes (not shown) for ejecting the combustion gas of the burner 2. Although only one of these spurge pipes 15 is drawn in FIG. 1, in reality, as shown in FIGS. 2 and 3, each of them extends in the Y direction and is arranged in large numbers in the X direction, and is a heat exchanger. Bubbles B containing combustion gas are supplied to the entire 32. The number of spurge pipes 15 and their arrangement are not particularly limited.

A manifold 17 is interposed between the downcomer 13 and each spudge pipe 15. The manifold 17 is connected to the lower end of the downcomer 13 and is arranged so as to extend in the X direction as shown in FIG. The base end of each spudge pipe 15 communicates with the manifold 17, and the manifold 17 has a function of distributing the combustion gas from the burner 2 to each spudge pipe 15. Each spurge pipe 15 has a circular cross section, and its tip is closed.

The top plate 11a of the water tank 11 is provided with a chimney-shaped stack 16 for exhausting the combustion gas ejected into the water tank 11, and the upper end thereof is open to the atmosphere.

The underwater combustion type vaporizer 1 ejects the combustion gas of the burner 2 into the water tank 11 as bubbles B through the bubble ejection holes of the spurge pipe 15, so that the water in the water tank 11 is agitated and the LNG flowing in the heat transfer tube 31 flows. To heat. As a result, LNG is vaporized to be NG, and this is sent out from the NG outlet pipe 12c. The underwater combustion type vaporizer 1 ejects combustion gas as bubbles B into the water tank 11 to agitate the water in the water tank 11, and sets the temperature of the exhaust gas discharged from the stack 16 to the temperature of the hot water in the water tank 11. By lowering it to almost the same level as, it is possible to recondense 100% of the combustion generated water in the combustion gas and give all the latent heat to the hot water, so that the thermal efficiency is extremely high.

Next, the configuration of the support member 4 that supports the heat transfer tube 31 of the heat exchanger 32 will be described in detail. As shown in FIGS. 2 and 3, the support member 4 is a plate-shaped member that extends orthogonally to the tube axis of the heat transfer tube 31 extending in the X direction. The support member 4 is erected on a foundation installed in the water tank 11. Five support members 4 are arranged in the X direction at predetermined intervals in the X direction. The heat transfer tube 31 is, for example, a circular tube made of stainless steel. The support member 4 is made of a synthetic resin, for example, a phenolic resin.

The support member 4 has a support hole 41 penetrating in the thickness direction, as shown in an enlarged part in FIG. 4, and the heat transfer tube 31 is inserted into the support hole 41. As described above, in the heat exchanger 32, a plurality of heat transfer tubes 31 are arranged side by side in each of the Y direction and the Z direction, and the support member 4 corresponds to each of the heat transfer tubes 31. As such, a plurality of support holes 41 are provided in a predetermined arrangement.

As shown in FIGS. 5 to 7, each support hole 41 has an inner peripheral surface 42 formed in a tapered shape. That is, the support hole 41 has a circular cross section, and the diameter of the opening 421 that opens in the first surface 411 of the support member 4 and the diameter of the opening 422 that opens in the second surface 412 are not the same. as shown in 5, the diameter phi ₂ of the opening 422 in the second surface 412 is smaller than the diameter phi ₁ of the opening 421 in the first surface 411. _{Further, the diameter φ 2} of the opening 422 on the second surface 412 is larger than the diameter φ 2 of the heat transfer tube 31.

As shown in FIGS. 6 and 7, the outer peripheral surface of the heat transfer tube 31 is an opening having a minimum diameter of the support hole 41 (that is, an opening opening in the second surface 412) with respect to the inner peripheral surface 42 of the support hole 41. In 422), the contact is made substantially at one point. In this way, the contact area between the outer peripheral surface of the heat transfer tube 31 and the inner peripheral surface 42 of the support hole 41 becomes smaller.

The water stored in the water tank 11 is generally industrial water and has a relatively high concentration of chloride ions. Further, when the underwater combustion type vaporizer 1 is used for emergency use, it may not be operated for a long period of time (for example, for a period of one year or two years). Therefore, in the underwater combustion type vaporizer 1, gap corrosion occurs in the heat transfer tube 31 at the contact point between the outer peripheral surface of the stainless steel heat transfer tube 31 and the inner peripheral surface 42 of the synthetic resin support hole 41. There is a risk. However, in the above configuration, since the contact area between the outer peripheral surface of the heat transfer tube 31 and the inner peripheral surface 42 of the support hole 41 is made as small as possible, it is possible to suppress crevice corrosion.

The heat transfer tube 31 does not always come into contact with the lowest position of the support hole 41 in the support hole 41. The position of the heat transfer tube 31 in the support hole 41 due to the relationship such as dimensional accuracy, the fact that a plurality of support members 4 are arranged at intervals, and the large number of heat transfer tubes 31 extending in the horizontal direction. Can also shift. In this regard, the fact that the support hole 41 has a circular cross-sectional shape with respect to the heat transfer tube 31 which is a circular tube means that the outer peripheral surface of the heat transfer tube 31 and the inner circumference of the support hole 41 are formed regardless of the position of the heat transfer tube 31. It is possible to always have one contact point with the surface 42. That is, it is possible to reduce the contact area in any of the large number of support holes 41.

_{Here, the larger the difference between the diameter φ 1} of the opening 421 on the first surface 411 _{and the diameter φ 2} of the opening 422 on the second surface 412, the larger the taper angle, and therefore the outer circumference of the heat transfer tube 31. It is advantageous in reducing the contact area between the surface and the inner peripheral surface 42 of the support hole 41. Moreover, as small as the diameter phi ₂ of the opening 422 in the second surface 412, also the difference between the diameter phi of the heat transfer tube 31, the larger is the contact point, the curvature difference between the two surfaces is increased, the contact area It will be advantageous in doing so.

The large number of support holes 41 provided in the support member 4 may all have the same taper direction, or the taper directions may be different.

The shape of the support hole is not limited to the shape described above. Hereinafter, a modified example of the shape of the support hole will be described with reference to the drawings. 8 (a) to 8 (c) show each example in which the support hole is formed by a curved line. 8 (a) to 8 (c) are views conceptually showing the shapes of the inner peripheral surfaces of the support holes, respectively.

First, FIG. 8A shows a support hole 51 having a circular cross section and a tapered inner peripheral surface. The difference between the support hole 51 in FIG. 8A and the support hole 41 shown in FIGS. 5 to 7 is the structure of the inner peripheral surface of the taper. The inner peripheral surface of the support hole 51 in FIG. 8A has a minimum diameter at the center in the thickness direction of the support member 4, and the diameter increases from there toward each of the first surface 411 and the second surface 412. It is configured as follows. Although not shown, the outer peripheral surface of the heat transfer tube 31 comes into contact with the inner peripheral surface of the support hole 51 at substantially one point at the portion having the smallest diameter in the support hole 51. It is preferable that the minimum diameter of the support hole 51 is larger than the outer diameter of the heat transfer tube 31 in order to reduce the contact area. The location of the minimum diameter is not limited to the center of the support member 4 in the thickness direction. The portion having the minimum diameter may be deviated from the center of the support member 4 in the thickness direction toward the first surface 411 or toward the second surface 412.

FIG. 8B shows a support hole 52 having an elliptical cross section and a tapered inner peripheral surface. The long axis of the ellipse of the support hole 52 may extend in the horizontal direction. Further, the long axis of the ellipse of the support hole 52 may extend in the vertical direction. Further, the minimum diameter (that is, the length of the minor axis) of the support hole 52 having an elliptical cross section is preferably larger than the diameter of the heat transfer tube 31. By doing so, it is possible to reduce the contact area between the outer peripheral surface of the heat transfer tube 31 and the minimum diameter portion of the support hole 51 as much as possible.

The support hole 53 shown in FIG. 8C has an elliptical cross section and has a minimum diameter at the center in the thickness direction of the support member 4, and has a diameter toward each of the first surface 411 and the second surface 412. Is configured to expand. The long axis of the ellipse of the support hole 53 may extend in the horizontal direction. Further, the long axis of the ellipse of the support hole 53 may extend in the vertical direction. Although not shown, the outer peripheral surface of the heat transfer tube 31 contacts the inner peripheral surface of the support hole 53 at the minimum diameter portion of the support hole 53. Even in the support hole 53 shown in FIG. 8C, it is advantageous that the minimum diameter of the support hole 53 is larger than the outer diameter of the heat transfer tube 31 in order to reduce the contact area between the two. The portion having the minimum diameter may be deviated from the center of the support member 4 in the thickness direction toward the first surface 411 or toward the second surface 412.

9 to 12 show each example in which the support holes are formed by straight lines. First, FIG. 9 shows a support hole 61 having a rectangular cross section. The cross section of the support hole 61 is square in the illustrated example, but may be rectangular. The support hole having a rectangular cross section may be vertically long vertically or horizontally long horizontally. As shown in FIG. 9, the inner peripheral surface 610 of the support hole 61 is formed in a tapered shape whose diameter decreases from the first surface 411 to the second surface 412. The minimum diameter of the support hole 61 is preferably larger than the diameter of the heat transfer tube 31. The "minimum diameter" of the support hole 61 referred to here corresponds to the distance between the opposite sides of the opening 612 of the second surface 412. The outer peripheral surface of the heat transfer tube 31 comes into contact with the inner peripheral surface 610 of the support hole 61 at the opening 612 having the smallest diameter in the support hole 61 having a rectangular cross section. Since the contact point is the contact between the curve of the outer peripheral surface of the heat transfer tube 31 and the straight line of the opening 612 in the support hole 61, it is substantially a point contact, and the contact area between the two is reduced. In the support hole 61 having a rectangular cross section shown in FIG. 9, when the heat transfer tube 31 makes contact only in the lower part of the support hole 61 as shown in the example, it is possible to make point contact and reduce the contact area. However, as described above, if the position of the heat transfer tube 31 is displaced, the outer peripheral surface of the heat transfer tube 31 may come into contact with both the lower portion and the side portion of the inner peripheral surface 610 of the support hole 61.

FIG. 10 shows the support hole 62 as a modified example of the support hole having a rectangular cross section. The inner peripheral surface of the support hole 62 has a minimum diameter at the center of the support member 4 in the thickness direction, and the diameter of the support hole 62 increases toward each of the first surface 411 and the second surface 412. There is. Although not shown, the outer peripheral surface of the heat transfer tube 31 contacts the inner peripheral surface of the support hole 62 at the minimum diameter portion of the support hole 62. Also in the support hole 62 of FIG. 10, it is advantageous that the minimum diameter is larger than the outer diameter of the heat transfer tube 31 in order to reduce the contact area. Further, the portion having the minimum diameter is not limited to the center in the thickness direction of the support member 4. The portion having the minimum diameter may be deviated from the center of the support member 4 in the thickness direction toward the first surface 411 or toward the second surface 412.

FIG. 11 shows the support hole 63 as an example in which the cross section is formed in a rhombus shape. The inner peripheral surface of the support hole 63 is formed in a tapered shape whose diameter decreases from the first surface 411 to the second surface 412. It is preferable that the minimum diameter of the support hole 63, that is, the distance between the sides facing each other in the opening 632 of the second surface 412 is larger than the diameter of the heat transfer tube 31. The outer peripheral surface of the heat transfer tube 31 comes into contact with the inner peripheral surface of the support hole 63 at two points in the opening 632 having the smallest diameter in the support hole 63 having a diamond-shaped cross section. Since each contact point is in contact with the curve of the outer peripheral surface of the heat transfer tube 31 and the straight line of the opening 632 having the smallest diameter in the support hole 63, it is substantially a point contact, and the contact area is reduced.

FIG. 12A shows the support hole 64 as a modified example of the support hole having a diamond-shaped cross section. The inner peripheral surface of the support hole 64 has a minimum diameter at the center in the thickness direction of the support member 4, and the diameter increases from there toward each of the first surface 411 and the second surface 412. There is. The minimum diameter of the support hole 64 is preferably larger than the diameter of the heat transfer tube 31. The outer peripheral surface of the heat transfer tube 31 comes into contact with the inner peripheral surface of the support hole 64 at two locations at the minimum diameter portion of the support hole 64 having a diamond-shaped cross section. Since the contact area of each portion is small, the contact area between the outer peripheral surface of the heat transfer tube 31 and the inner peripheral surface of the support hole 64 is also small. The location of the minimum diameter is not limited to the center of the support member 4 in the thickness direction. The portion having the minimum diameter may be deviated from the center of the support member 4 in the thickness direction toward the first surface 411 or toward the second surface 412.

FIG. 12B illustrates a support hole 65 having a triangular cross section. The support hole 65 has an inverted triangular shape when viewed from the front. The inner peripheral surface of the support hole 65 is formed in a tapered shape. The minimum diameter of the support hole 65 is preferably larger than the diameter of the heat transfer tube 31. By doing so, it is possible to prevent the outer peripheral surface of the heat transfer tube 31 from coming into contact with the inner peripheral surface of the support hole 65 at three points. The outer peripheral surface of the heat transfer tube 31 comes into contact with the inner peripheral surface of the support hole 65 at two points at the minimum diameter portion of the support hole 65 having a triangular cross section. Since each contact point is in contact with the curve of the outer peripheral surface of the heat transfer tube 31 and the straight line of the inner peripheral surface of the support hole 65, it is substantially a point contact, and the contact area is reduced.

FIG. 12C shows the support hole 66 as a modified example of the support hole having a triangular cross section. The inner peripheral surface of the support hole 66 is formed by combining two tapers. The portion having the smallest diameter of the support hole 66 is located at the center of the support member 4 in the thickness direction. The minimum diameter of the support hole 66 is preferably larger than the diameter of the heat transfer tube 31. In the support hole 66 as well, similarly to the support hole 65 shown in FIG. 12B, the outer peripheral surface of the heat transfer tube 31 is the inner circumference of the support hole 66 at the minimum diameter portion of the support hole 66 having a triangular cross section. It comes into contact with the surface at two points. Since each contact point is in contact with the curve of the outer peripheral surface of the heat transfer tube 31 and the straight line of the inner peripheral surface of the support hole 66, it is substantially a point contact, and the contact area is reduced.

In the support holes 41, 51, 52, 53, 61, 62, 63, 64, 65, 66 of each configuration described above, the inner peripheral surface of the support hole in contact with the outer peripheral surface of the heat transfer tube 31 is shown in FIG. As shown, a plurality of concave grooves 81 extending in the direction along the tube axis of the heat transfer tube 31 may be formed in a striped shape. By doing so, the contact area at the contact point between the outer peripheral surface of the heat transfer tube 31 and the inner peripheral surface of the support holes 41, 51, 52, 53, 61, 62, 63, 64, 65, 66 can be further reduced. Becomes possible.

Unlike this, as shown in FIG. 14, the inner peripheral surfaces of the support holes 41, 51, 52, 53, 61, 62, 63, 64, 65, 66 are provided with a large number of convex portions to form a grid. A recess 82 may be provided. By doing so, the contact area at the contact point between the outer peripheral surface of the heat transfer tube 31 and the inner peripheral surface of the support holes 41, 51, 52, 53, 61, 62, 63, 64, 65, 66 can be further reduced. Becomes possible.

FIG. 15 shows a modified example of the support hole. The support hole 71 includes two protrusions 710 that project inward in the radial direction from the inner peripheral surface thereof. The outer peripheral surface of the heat transfer tube 31 is in contact with the two protrusions 710. At the contact point between the outer peripheral surface of the heat transfer tube 31 and the inner peripheral surface of the support hole 71,
The inner peripheral surface of the support hole 71 formed by the protrusions 710 has an angle of 180 ° or more with respect to the outer peripheral surface of the heat transfer tube 31, and the outer peripheral surface of the heat transfer tube 31 and the inner peripheral surface of the support hole 71. Is substantially a point contact. The support hole 71 having this configuration also suppresses crevice corrosion by reducing the contact area between the outer peripheral surface of the heat transfer tube 31 and the inner peripheral surface of the support hole 71.

The technique disclosed here is not limited to the underwater combustion type vaporizer 1, and is an intermediate heat medium type vaporizer including a steam ejector type vaporizer having a spurge pipe arranged in the water tank. It is also possible to apply to. Further, it can be widely applied not only to a low-temperature liquefied gas vaporizer but also to a heat exchanger of a heat exchanger immersed in a water tank, which raises the temperature of a fluid flowing in a heat transfer tube.

1 Underwater combustion type vaporizer (heat exchange device)
11 Water tank 15 Spare pipe 31 Heat transfer tube 32 Heat exchanger 4 Support members 41, 51, 52, 53, 61, 62, 63, 64, 65, 66 Support holes 42, 610 Inner peripheral surface 81 Concave groove 82 Concave

Claims (3)

A spurge pipe that is immersed in a water tank and is configured to eject high-temperature gas into the water.
It has a heat transfer tube arranged above the spurge pipe in the water tank, and is configured to raise the temperature of the fluid flowing inside the spurge pipe by stirring and heating water by bubbles ejected from the spurge pipe. With a heat exchanger
A support member immersed in the water tank and configured to support the heat transfer tube is provided.
The support member is a plate-shaped member that extends so as to be orthogonal to the tube axis of the heat transfer tube, and has a support hole through which the heat transfer tube penetrates.
The inner peripheral surface of the support hole is formed in a tapered shape in the thickness direction of the support member.
The minimum diameter of the support hole is larger than the outer diameter of the heat transfer tube.
The heat transfer tube is a heat exchange device that is supported by contacting an edge-shaped portion having the minimum diameter of the support hole so as to make point contact or line contact. In the heat exchange device according to claim 1,
A heat exchange device in which a plurality of concave grooves extending in a direction along the tube axis of the heat transfer tube are formed in a striped pattern on the inner peripheral surface of the support hole. In the heat exchange device according to claim 1,
A heat exchange device in which a grid-like recess is formed on the inner peripheral surface of the support hole.

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