JP6525606B2 - Low temperature liquefied gas vaporizer - Google Patents

Description

  The technology disclosed herein relates to a low temperature liquefied gas vaporization apparatus.

  Patent Literature 1 describes a submerged combustion vaporizer as one of the low-temperature liquefied gas vaporizers. The underwater combustion type vaporization device is one of the vaporization devices of low temperature liquefied gas such as liquefied natural gas, and is immersed in a water tank and ejects the combustion gas from the burner into water through bubble injection holes formed on the peripheral surface. And a heat exchanger having a heat transfer pipe disposed above the sparge pipe in the water tank. The combustion gas jetted out as bubbles in water stirs the water in the water tank and heats the low temperature liquefied gas flowing in the heat transfer pipe. This vaporizes the low temperature liquefied gas.

  In addition, as a submerged combustion type vaporization device, as a vaporization device that vaporizes low temperature liquefied gas flowing in a heat transfer pipe immersed in a water tank by spouting high temperature gas as bubbles from a sparge pipe disposed in the water tank, Also known are intermediate heat medium vaporizers, such as steam ejector vaporizers.

JP, 2013-2734, A

  As described above, in each sparge pipe installed in the water tank, a bubble jet hole is formed on the circumferential surface, and the bubble jet hole is generally provided in the upper surface portion of the sparge pipe. The bubbles ejected into the water through the bubble ejection holes rise as they are and reach the heat transfer tubes of the heat exchanger. The temperature of the gas ejected into the water tank is close to 1000 ° C., while the temperature of the low temperature liquefied gas flowing in the heat transfer tube is about -160 ° C. The bubbles and the water heated by the bubbles ascend as they expelled from the sparge pipe, causing the bubbles and the surrounding water to vigorously collide with the heat transfer tube, and the heat in the heat transfer tube Transmission is strengthened. In addition, air bubbles ejected from the sparge pipe immediately reach the heat transfer tube before the temperature decreases, and heat the outside of the heat transfer tube. Therefore, the temperature difference between the inside and the outside of the heat transfer tube is increased, and the thermal stress acting on the heat transfer tube is increased.

  The underwater combustion type vaporization device and the intermediate heat medium type vaporization device are also used for emergency to cover a rapid increase in demand, and start and stop may be repeated. Therefore, the increase in the temperature difference between the inside and the outside of the heat transfer tube causes thermal fatigue of the heat transfer tube.

  The technique disclosed herein has been made in view of the above point, and is to suppress thermal stress and thermal fatigue of a heat transfer tube in a low temperature liquefied gas vaporization device.

  The technology disclosed herein relates to a low-temperature liquefied gas vaporization apparatus, which has a plurality of sparge pipes immersed in a water tank and having a large number of bubble injection holes formed on the circumferential surface, and a high-temperature gas A bubble injection mechanism configured to eject water into the water through the bubble injection holes, and agitation and heating of water by the air bubbles disposed above the bubble injection mechanism in the water tank and ejected from the sparge pipe. And a heat exchanger configured to vaporize the low temperature liquefied gas flowing inside the heat transfer tube.

Then, each of the plurality of the Supajipaipu, together are arranged to extend from the proximal end is the inflow end of the high-temperature gas in a predetermined direction, the tip is closed, the air bubble ejection mechanism, said Supajipaipu the The heat transfer tube of the heat exchanger has a baffle plate interposed between the heat transfer tube and the air bubbles ejected from the bubble injection holes of at least a part of the sparge pipe while bypassing the baffle plate. It is configured to reach.

  According to this configuration, in the water tank, the bubble jetting mechanism having the sparge pipe is disposed on the lower side, and the heat exchanger having the heat transfer tube is disposed on the upper side. The bubbles of the high temperature gas spouted from the sparge pipe ascend to agitate the water in the water tank and heat the low temperature liquefied gas flowing in the heat transfer tube together with the water heated by the bubbles. Thus, the low temperature liquefied gas is vaporized.

In the above configuration, the air bubbles ejected from the air bubble injection holes of at least a part of the sparge pipe bypass the baffle plate and reach the heat transfer pipe of the heat exchanger. The bubbles are diverted, that is, the bubbles spouted into the water from the bubble spouts of the sparge pipe rise with the spout force, and do not immediately reach the heat transfer tubes of the heat exchanger, but go around, It means reaching the heat transfer tube of the heat exchanger. By bypassing the baffle plate , the bubbles do not rise as they are spouted, and after they weaken, they rise mainly by buoyancy and reach the heat transfer tubes. Thus, the air bubbles and the water around them are prevented from vigorously colliding with the heat transfer tube, so the heat transfer in the heat transfer tube is weakened accordingly.

Also, by bypassing the baffle plate , the air bubbles are spouted from the sparge pipe into the water and then rise as it is, and then travel a distance longer than the distance to reach the heat transfer tubes of the heat exchanger immediately to the heat transfer tubes. To reach. Alternatively, the heat transfer tube is reached in a longer time than the heat transfer tube is immediately reached. While bypassing the baffle plate , heat is exchanged between the air bubbles and the water in the water tank, so that the air bubbles decrease in temperature. The temperature of the bubble when the bubble reaches the heat transfer tube is lower than that when the bubble does not bypass and reaches the heat transfer tube.

  Thus, the temperature difference between the inside and the outside of the heat transfer tube is reduced, and the thermal stress acting on the heat transfer tube is suppressed. In addition, thermal fatigue of the heat transfer tube is also suppressed.

  At least a part of the air bubble injection holes formed on the circumferential surface of the sparge pipe may be bypass air bubble injection holes provided such that the hole axis thereof is lower than the horizontal direction.

  The air bubbles ejected from the bypass bubble ejection holes whose hole axis is downward move downward in the water tank and, after the momentum of the ejection is almost lost, they turn up and reach the heat transfer tube. Since the air bubble and the surrounding water do not collide with the heat transfer tube vigorously, excessive heat transfer in the heat transfer tube is suppressed.

  In addition, the air bubbles are diverted by the amount of downward movement, and the temperature of the air bubbles when reaching the heat transfer tube is lowered. In particular, if a bubble jet hole is formed near the lower end of the sparge pipe, the hole axis will be almost straight down, so it moves downward in the water tank and turns upward, then rises while avoiding the sparge pipe. To reach. In this case, the bubble detour distance is further increased, or the time to reach the heat transfer tube is further lengthened, so the temperature of the bubble when reaching the heat transfer tube is further lowered.

  By setting the hole axis of the bubble injection hole to be lower than horizontal, suppression of the thermal stress of the heat transfer tube and suppression of thermal fatigue are effectively performed.

  The bypass bubble injection hole may be provided at a proximal end of the sparge pipe.

  The proximal end of the sparge pipe tends to have a relatively large amount of bubbles ejected as compared to the distal end, but the above-mentioned bubble jet hole provided at the proximal end of the sparge pipe serves as the bypass bubble jet hole. As a result, air bubbles and water around them are not vigorously collided with the heat transfer tube located above the proximal end of the sparge pipe, so that the thermal stress of the heat transfer tube and the thermal fatigue can be suppressed.

  Here, the base end portion of the sparge pipe may be at least a part of the base end side of the sparge pipe extending in the predetermined direction when the portion in which the bubble injection holes are formed is bisected in the predetermined direction, Further, the tip end portion of the sparge pipe may be at least a part of the tip end side when the portion in which the bubble injection holes are formed is divided into two equal parts.

  The bypass bubble injection hole may be provided from the proximal end to the distal end of the sparge pipe.

  In this way, air bubbles and water around them do not vigorously collide with the heat transfer tube located above the entire proximal end to the tip of the sparge pipe, and the thermal stress of the heat transfer tube can be reduced. Suppression and thermal fatigue can be suppressed.

  Also, when a high temperature gas is supplied into the sparge pipe, the high temperature gas will be accumulated at the top in the sparge pipe. When the bubble injection holes are provided in the upper surface portion of the sparge pipe, the high temperature gas accumulated in the upper part is jetted out one after another from the proximal end in the sparge pipe. As a result, it becomes difficult for the high temperature gas to reach the tip of the sparge pipe. That is, the proximal end portion of the sparge pipe has a large amount of air bubble ejection, and the tip end portion has a small amount of air bubble ejection, and the amount of air bubble ejection tends to be uneven in the longitudinal direction of the sparge pipe.

  On the other hand, the bypass bubble spouting holes whose hole axes are less than horizontal are formed in the lower portion of the sparge pipe (generally circular in cross section). Therefore, in the configuration in which the bypass bubble ejection holes are provided from the base end to the tip end of the sparge pipe, even if high temperature gas is accumulated in the upper portion in the sparge pipe, the bypass bubble ejection holes formed on the lower side of the sparge pipe After the high temperature gas is not ejected and the gas is accumulated in the entire upper part from the tip to the proximal end of the sparge pipe, the high temperature gas is passed through the downward bypass bubble injection holes all over the entire part from the tip to the proximal end of the sparge pipe Will be spouted. That is, in the configuration in which the bypass bubble ejection holes are provided from the proximal end to the distal end of the sparge pipe, it is possible to equalize the bubble ejection amount in the longitudinal direction of the sparge pipe.

  Thus, as a result of equalizing the bubble ejection amount in the longitudinal direction of the sparge pipe, it is also possible to suppress the thermal stress and thermal fatigue of the heat transfer pipe located above the proximal end of the sparge pipe.

  The hole axis of the bypass bubble injection hole provided at the base end of the sparge pipe has an angle with respect to the vertically upward direction larger than the angle of the hole axis of the air bubble injection hole provided at the tip of the sparge pipe , May be.

  Here, the bubble injection hole provided at the tip of the sparge pipe may be a bypass bubble injection hole whose hole axis is lower than horizontal, or the hole axis is a horizontal air or a bubble injection hole higher than horizontal. It may be.

  According to the above configuration, the hole axis of the bypass bubble ejection hole provided at the base end of the sparge pipe has a large angle with respect to the vertical upper side, so that the bubble ejected from the bypass bubble ejection hole moves downward largely. Ascend and reach the heat transfer tube. As a result, the detour distance of the bubbles is further increased, so that the temperature of the bubbles when reaching the heat transfer tube is further lowered, and the bubbles and the water around them are prevented from vigorously colliding with the heat transfer tube .

  A cold water zone may be provided below the sparge pipe. In this way, the air bubbles jetted downward into the water tank through the bypass bubble jet holes whose hole axis is lower than the horizontal direction promote heat exchange in the cold water area provided below the sparge pipe. As a result, it is possible to further lower the temperature of the air bubbles when reaching the heat transfer tube.

  The baffle plate may be disposed at a proximal end of the sparge pipe.

  In this way, at the proximal end of the sparge pipe, the baffle plate can divert air bubbles to reach the heat transfer pipe, so that the heat transfer pipe located above the proximal end of the sparge pipe The water around it does not collide vigorously, and the thermal stress of the heat transfer tube can be suppressed and the thermal fatigue can be suppressed.

  The baffle plate may be disposed from the proximal end to the distal end of the sparge pipe.

  In this way, air bubbles and water around them do not vigorously collide with the heat transfer tube located above the entire proximal end to the tip of the sparge pipe, and the thermal stress of the heat transfer tube can be reduced. Suppression and thermal fatigue can be suppressed.

  The baffle plate may be disposed on the heat transfer tube side between the sparge pipe and the heat transfer tube.

  This makes it possible to more reliably prevent the air bubbles and the surrounding water from vigorously colliding with the heat transfer tubes.

  The baffle plate may be provided with a through hole. By doing this, some air bubbles will pass through the through holes of the baffle plate, but at that time, the rising speed will be reduced, and the air bubbles and the water around them will move to the heat transfer tube vigorously. A collision is prevented. In addition, if the size of the air bubbles after passing through the through holes of the baffle plate is reduced, heat exchange between the air bubbles and water takes place while the air bubbles reach the heat transfer tube, together with the decrease of the rising speed. As a result of the acceleration, the temperature of the air bubble when reaching the heat transfer tube can be reduced.

  In addition, when providing a through-hole in a baffle plate, it is desirable to provide a through-hole in a baffle plate to such an extent that at least one part air bubbles bypass a baffle plate and reach a heat exchanger tube.

As described above, according to the low-temperature liquefied gas vaporization device, the bubbles ejected from the sparge pipe reach the heat transfer tubes of the heat exchanger while bypassing the baffle plate, whereby the bubbles and their surroundings Of the water in the heat transfer tube is avoided, heat exchange between the air bubble and the water in the water tank is promoted, and the temperature of the air bubble when it reaches the heat transfer tube can be lowered. become. As a result, the temperature difference between the inside and the outside of the heat transfer tube is reduced, the thermal stress is suppressed, and the thermal fatigue of the heat transfer tube is suppressed.

It is a conceptual diagram which shows the whole structure of a submersible combustion type vaporization apparatus. It is a front view which shows the reference form of the heat exchanger arrange | positioned in a water tank, and a bubble injection mechanism. It is a top view of the heat exchanger and bubble injection mechanism shown in FIG. It is a side view of the heat exchanger and bubble injection mechanism shown in FIG. It is a bottom view which shows the sparge pipe of the bubble injection mechanism shown in FIG. It is cross-sectional explanatory drawing of the bubble injection mechanism shown in FIG. It is a bottom view which shows the sparge pipe which concerns on the modification of a reference form . It is a top view which shows the heat exchanger and bubble injection mechanism which concern on embodiment . It is a side view of the heat exchanger and bubble injection mechanism shown in FIG. It is cross-sectional explanatory drawing of the bubble injection mechanism shown in FIG. It is a side view of the heat exchanger and bubble injection mechanism concerning a modification.

Hereinafter, an embodiment of a low temperature liquefied gas vaporization apparatus will be described based on the drawings. FIG. 1 shows an outline of the entire underwater combustion type vaporizer 1. FIGS. 2 to 4 show the reference configurations of the heat exchanger 32 and the bubble jetting mechanism 100 immersed in the water tank 11, respectively. The underwater combustion type vaporization device 1 is one of the vaporization devices of low temperature liquefied gas, and in this case, liquefied natural gas (LNG) is vaporized.

  The submersible combustion type vaporization device 1 is provided with a heat exchanger 32 which is, for example, immersed in a rectangular water tank 11 and formed by bending a large number of heat transfer pipes 31 serving as a flow path of LNG in multiple stages. . One end of each heat transfer pipe 31 communicates with an LNG inflow pipe 12b serving as an inlet for LNG, and the other end communicates with an NG discharge pipe 12c that discharges vaporized natural gas (NG). In FIG. 1, although the heat transfer tube 31 is simplified and shown in figure, many heat transfer tubes 31 are arrange | positioned along with the Y direction in fact, as shown to FIGS. 31 communicates with the header tank 33 connected to the LNG inflow pipe 12 b and the header tank 34 connected to the NG discharge pipe 12 c. The number of heat transfer tubes 31 and the arrangement thereof are appropriately determined according to the performance of the underwater combustion type vaporization device 1.

  The water tank 11 is covered with, for example, a rectangular top 11a. A worker can walk on the top plate 11 a, and a cylindrical downcomer 13 is disposed in the water tank 11 so as to be immersed in the predetermined portion.

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

  At the bottom of the water tank 11, a sparge pipe 15 communicating with the downcomer 13 and provided with a large number of bubble injection holes (not shown in FIG. 1 and the like) from which the combustion gas of the burner 2 is jetted is disposed. There is. Although only one such sparge pipe 15 is drawn in FIG. 1, in actuality, as shown in FIGS. 2 to 4, a large number of each are extended in the Y direction and arranged in the X direction. The bubble B containing the combustion gas is supplied to the whole 32. The number of sparge pipes 15 and the arrangement thereof are not particularly limited. The plurality of sparge pipes 15 constitute a bubble ejection mechanism 100 that ejects the combustion gas into the water tank 11 as the bubbles B.

  A manifold 17 is interposed between the downcomer 13 and each sparge pipe 15. The manifold 17 is connected to the lower end portion of the downcomer 13 as shown in FIG. 4 and extends in the X direction as shown in FIG. In FIGS. 1 and 4, the arrangement of the manifold 17 and the direction of the sparge pipe 15 are reversed. The proximal end of each sparge pipe 15 is in communication with a manifold 17, and the manifold 17 has a function of distributing the combustion gas from the burner 2 to each sparge pipe 15. The tip of each sparge pipe 15 is closed.

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

  The underwater combustion type vaporization device 1 is an LNG flowing through the heat transfer tube 31 while stirring the water in the water tank 11 by causing the combustion gas of the burner 2 to be ejected as the bubbles B into the water tank 11 through the bubble injection holes of the sparge pipe 15. Heat up. As a result, the LNG is vaporized to be an NG, which is sent out from the outlet of the NG discharge pipe 12c. The submersible combustion type vaporization device 1 jets combustion gas as bubbles B into the water tank 11 to stir the water in the water tank 11, and the temperature of the exhaust gas discharged from the stack 16 as the temperature of the hot water in the water tank 11 By making the temperature about the same as the above, it is possible to recondense the combustion generated water in the combustion gas by 100%, and all the latent heat can be given to the hot water, so that the thermal efficiency is extremely high.

  Next, a reference configuration of the bubble jetting mechanism 100 having the sparge pipe 15 will be described in detail with reference to the drawings. In such an underwater combustion type vaporization device 1, the temperature of the combustion gas ejected into the water tank 11 is close to 1000 ° C., while the temperature of the LNG flowing in the heat transfer tube 31 is about −160 ° C. Therefore, the temperature difference between the inside and the outside of the heat transfer tube 31 is increased, and the thermal stress acting on the heat transfer tube 31 is increased. Moreover, the underwater combustion type vaporization apparatus 1 is also used as an emergency for covering a rapid increase in demand, and the start and stop may be repeated. The large temperature difference between the inside and the outside of the heat transfer tube 31 causes thermal fatigue of the heat transfer tube 31.

  So, in this underwater combustion type vaporization apparatus 1, the bubble injection mechanism 100 is comprised so that the thermal stress and thermal fatigue of the heat exchanger tube 31 of the heat exchanger 32 may be suppressed. FIG. 5 is a bottom view of the sparge pipe 15. As described above, the large number of bubble injection holes 151 are formed in the circumferential surface of the sparge pipe 15. The air bubble injection hole 151 is formed over a wide range in the longitudinal direction from the closed distal end side (left side in FIG. 5) of the sparge pipe 15 to the proximal end side (right side in FIG. 5) connected to the manifold 17. . In the illustrated example, in the illustrated example, the row of holes extending in the longitudinal direction of the sparge pipe 15 is formed to form five rows in the circumferential direction, and the bubble outlet 151 of the adjacent row of holes is in the shape of a rhombus grid. It is arranged to become. The arrangement of the bubble injection holes 151 is not limited to the rhombic lattice shape. The bubble ejection holes 151 may be arranged, for example, in a rectangular grid shape. Also, other configurations can be adopted as appropriate. The diameters of the bubble injection holes 151 are all the same.

  FIG. 6 shows a VI-VI cross section of FIG. The sparge pipe 15 is circular in cross section, and the bubble injection hole 151 is provided on the lower surface portion of the sparge pipe 15 in the water tank 11. Each air bubble injection hole 151 is provided through the sparge pipe 15 so that the hole axis passes through the center of the circle. As described above, the bubble jetting holes 151 formed in five rows in the circumferential direction (three rows are drawn in the cross section shown in FIG. 6) are circumferentially centered on the lower end of the sparge pipe 15 Each of the two sides of the angle .alpha. In the illustrated example, the angle θ formed by the hole axis of the air bubble injection hole 151 is set to 60 °. The angle with respect to the vertical upper side of the hole axis of each bubble injection hole 151 is included in the range of 180 ° ± 30 °. Thus, all the hole axes of the bubble injection holes 151 formed in the sparge pipe 15 are set to be more downward than the horizontal line shown by a broken line in FIG. It spouts into the water downward from the horizontal. The bubble injection holes 151 correspond to bypass bubble injection holes, and the sparge pipe 15 is provided with bypass gas injection holes from the base end to the tip of the sparge pipe 15.

  As indicated by the arrows in FIG. 6, the air bubbles B ejected into the water move downward downward from the air bubble injection holes 151 provided on the lower surface portion of the sparge pipe 15, and after the momentum of the injection is weakened, It turns to rise mainly by buoyancy. Then, the air bubble B reaches the heat transfer pipe 31 disposed on the upper side of the sparge pipe 15, which is virtually shown in FIG. In particular, the air bubbles B ejected from the air bubble injection holes 151 provided near the lower end of the sparge pipe 15 move upward almost immediately and then turn to rise, but the air bubbles B rise while bypassing the sparge pipe 15, The heat transfer tube 31 is reached. Thus, by turning the hole axis of the bubble injection hole 151 downward, the bubble B does not rise as it is ejected, but detours to reach the heat transfer tube 31, and the air bubble It is avoided that the surrounding water collides with the heat transfer tube 31 vigorously. Further, the air bubble B travels in the water tank 11 by an amount corresponding to the detour. Or, the time to reach the heat transfer tube 31 becomes long. In the meantime, since heat exchange is performed between the air bubble B and the water in the water tank 11, the temperature of the air bubble B when reaching the heat transfer tube 31 becomes low.

  Further, as shown in FIGS. 2 and 4, in the water tank 11, a relatively wide space is provided between the sparge pipe 15 and the bottom of the water tank 11, and the sparge pipe 15 and the bottom of the water tank 11 are provided. In the meantime, the cold water region 110 has a relatively low water temperature. As a result of the heat exchange in the cold water zone 110 being promoted, the temperature of the air bubbles B ejected downward is further lowered. Thus, the temperature when the air bubble B detours and reaches the heat transfer tube 31 is lower than the temperature when the air bubble B reaches the heat transfer tube 31 without detouring.

  As described above, the difference between the temperature of the combustion gas spouted from the sparge pipe 15 and the temperature of the LNG flowing in the heat transfer pipe 31 is large, and the bubbles B spouted from the spurge pipe 15 remain as they are spouted from the sparge pipe 15 When the temperature rises and collides with the heat transfer tube 31 with the surrounding water while maintaining high temperature, the heat transfer in the heat transfer tube 31 is enhanced, and the temperature difference between the inside and outside of the heat transfer tube 31 becomes large. Since the bubble ejection mechanism 100 is configured such that the bubble B detours and reaches the heat transfer tube 31, the bubble and the water around it are prevented from vigorously colliding with the heat transfer tube, and the heat transfer tube 31 It is possible to lower the temperature of the bubble B when it reaches. As a result, the temperature difference between the inside and the outside of the heat transfer tube 31 becomes smaller, and the thermal stress acting on the heat transfer tube 31 is suppressed. Further, in the underwater combustion type vaporization device 1 in which start and stop are repeated, thermal fatigue of the heat transfer tube 31 can be suppressed by reducing the temperature difference between the inside and the outside of the heat transfer tube 31.

  When the combustion gas is supplied into the sparge pipe 15, the combustion gas is accumulated in the upper portion in the sparge pipe 15, as shown virtually in FIG. In the bubble jetting mechanism 100, the bubble jetting hole 151 is formed in the lower surface portion of the sparge pipe 15, and is not formed in the upper surface portion. Therefore, after the combustion gas is accumulated in the upper part over the entire region in the longitudinal direction of the sparge pipe 15, the combustion gas is ejected as the bubbles B all at once from the bubble injection holes 151 of the entire region in the longitudinal direction. . This will equalize the bubble ejection amount in the longitudinal direction of the sparge pipe 15. That is, in the conventional underwater combustion type vaporization apparatus in which the bubble injection holes are provided on the upper surface portion of the sparge pipe, the combustion gas accumulated in the upper part in the sparge pipe is successively supplied from the bubble injection holes provided on the proximal end side of the sparge pipe. Since the gas is spouted, it becomes difficult for the combustion gas to spread to the tip side of the sparge pipe. As a result, the base end of the sparge pipe has a relatively large amount of bubble ejection, and the tip has a relatively small amount of bubble ejection. For this reason, the heat transfer tube located above the proximal end of the sparge pipe is particularly susceptible to the above-mentioned thermal stress and thermal fatigue.

  On the other hand, in the bubble jetting mechanism 100 configured as described above, the amount of bubble jetting is equalized in the longitudinal direction of the sparge pipe 15, so thermal stress and heat of the heat transfer tube 31 located above the base end of the sparge pipe 15 It becomes possible to suppress fatigue.

  The air bubble injection hole 151 formed on the circumferential surface of the sparge pipe 15 may be such that the hole axis is directed downward rather than horizontal. Therefore, in the case of providing the bubble injection hole 151 on the circumferential surface of the sparge pipe 15 so that the hole axis passes through the center of the circle in the sparge pipe 15 having a circular cross section, the bubble injection hole 151 may be provided in the lower half of the sparge pipe 15 . However, in order to make the detour distance of the air bubble B as long as possible, it is preferable to provide the air bubble injection hole 151 near the lower end of the sparge pipe 15. For example, the bubble ejection holes 151 may be provided in an angle range in which the angle θ formed by the hole axes of the bubble ejection holes 151 is 90 ° or less on both sides in the circumferential direction centering on the lower end of the sparge pipe 15.

  Further, the diameters of the bubble injection holes 151 may not be all the same, but may be changed according to the longitudinal position of the sparge pipe 15. For example, the diameter of the air bubble injection hole 151 provided at the base end of the sparge pipe 15 may be relatively small, and the diameter of the air bubble injection hole 151 provided at the tip of the sparge pipe 15 may be relatively large. This prevents the bubble ejection amount from becoming uneven in the longitudinal direction of the sparge pipe 15.

  Furthermore, as a modification, according to the position of the sparge pipe 15 in the longitudinal direction, the angle with respect to the vertical upper side of the hole axis of the bubble injection hole 151 may be changed. For example, FIG. 7 is a bottom view of a sparge pipe 15 according to a modification. As shown in the same figure, at the base end when the portion where the bubble injection hole 151 is formed in the sparge pipe 15 is equally divided into three at the base end portion, the middle portion and the tip end portion, the bubble injection hole 151 is While provided on the lower surface of the sparge pipe 15, the air bubble ejection hole 151 is provided on the side surface of the sparge pipe 15 at the tip end, and further, the air bubble ejection hole 151 is provided between the lower surface and the side surface of the sparge pipe 15 May be Each bubble injection hole 151 is provided such that the hole axis passes through the center of the circle. In this configuration, the hole axis of the air bubble injection hole 151 provided at the base end of the sparge pipe 15 has an angle (that is, about 180 °) with respect to the vertically upward direction of the hole axis of the air bubble injection hole 151 provided at the tip of the sparge pipe 15 (Ie, about 90 °).

  By doing this, at least the bypass bubble injection holes are provided at the base end portion and the middle portion of the sparge pipe 15, and thermal stress is generated in the heat transfer pipe 31 located above the base end portion and the middle portion of the sparge pipe 15. Of thermal fatigue and thermal fatigue. This configuration also suppresses the occurrence of uneven bubble ejection amount in the longitudinal direction of the sparge pipe 15.

  Note that, unlike the configuration example of FIG. 7, the air bubble injection hole 151 may be provided on the top surface of the sparge pipe 15 at the tip of the sparge pipe 15. In that case, the air bubble injection hole 151 may be provided on the side surface of the sparge pipe 15 in the middle part of the sparge pipe 15.

  Further, in the configuration example of FIG. 7, the angle of the hole axis of the air bubble injection hole 151 is changed stepwise from the tip end side to the base end side of the sparge pipe 15, but unlike this, the sparge pipe As a result of continuously changing the angle of the hole axis of the air bubble injection hole 151 from the distal end side to the proximal end side of 15, the hole axis of the air bubble injection hole 151 provided at the proximal end becomes downward than horizontal You may do so.

  Further, in the example of FIG. 7, the portion of the sparge pipe 15 where the bubble injection holes 151 are formed is equally divided into three of the tip end portion, the middle portion and the base end portion, and the hole axis of the bubble injection holes 151 in each portion For example, after the portion of the sparge pipe 15 in which the bubble injection holes 151 are formed is equally divided into two of the tip end portion and the base end portion, the bubble injection holes are formed at the base end portion. The angle of the hole axis relative to the vertical upper side may be made relatively large, and the angle of the hole axis may be made relatively small at the tip, so that the hole axis of 151 is lower than horizontal. At this time, the hole axis of the air bubble injection hole 151 provided at the tip end may be lower than horizontal, or may be higher horizontal or horizontal. The bypass bubble injection hole whose hole axis is lower than horizontal may be provided only at the proximal end of the sparge pipe 15. In addition, the division | segmentation number which concerns on the change of the height position of the bubble injection hole 151 may be suitably set by 4 or more not only in 2 or 3.

  In addition, the air bubble injection hole 151 provided in the surrounding surface of the sparge pipe 15 is not limited to providing the hole axis so that the center of a circle may be passed.

8 to 10 show an embodiment of the bubble jetting mechanism. The bubble jetting mechanism 101 is configured to include a sparge pipe 15 and a baffle plate 152. The baffle plate 152 is interposed between the sparge pipe 15 and the heat transfer pipe 31 corresponding to each sparge pipe 15.

  In the bubble jetting mechanism 101, the bubble jetting holes 151 are provided on the upper surface portion of the sparge pipe 15, as shown in FIG. The air bubble injection holes 151 are formed in a predetermined angular range on both sides in the circumferential direction centering on the upper end of the sparge pipe 15. Therefore, contrary to the above-mentioned configuration, the hole axis of the air bubble injection hole 151 is upward than horizontal. Further, the air bubble injection holes 151 formed in the upper surface portion of the sparge pipe 15 are configured similarly to the arrangement of the air bubble injection holes 151 shown in FIG. 5, and from the closed tip side (left side in FIG. 5) of the sparge pipe 15 A wide range in the longitudinal direction up to the proximal end side (right side in FIG. 5) connected to the manifold 17 is formed in a predetermined arrangement.

  The baffle plate 152, as shown in FIG. 8, has a substantially arc shape whose cross section is convex upward, and extends along the longitudinal direction of the sparge pipe 15 as shown in FIG. It is set up. Thus, the baffle plate 152 extends in the circumferential direction and extends in the longitudinal direction so as to cover the whole of the bubble injection holes 151 provided in the sparge pipe 15.

  As shown in FIG. 10, in the bubble jetting mechanism 101 of this configuration, the bubble jetting hole 151 is provided on the upper surface portion of the sparge pipe 15, so the bubble B jetted upward from the bubble jetting hole 151 Although rising, it is blocked by the baffle plate 152. Therefore, the air bubble B can not reach the heat transfer tube 31 as it is spouted from the sparge pipe 15, and bypasses the baffle plate 152 to reach the heat transfer tube 31 as shown by the arrow in FIG. . Similar to the above configuration, by bypassing, the air bubbles are mainly lifted by buoyancy, and the air bubbles and the water around them are avoided while vigorously colliding with the heat transfer tube 31 and are bypassed. The moving distance of the air bubble B is increased by an amount. Or, the time to reach the heat transfer tube 31 becomes long. This makes it possible to lower the temperature of the air bubble B when reaching the heat transfer tube 31. Therefore, also in the bubble ejection mechanism 101 of this configuration, it is possible to reduce the temperature difference between the inside and the outside of the heat transfer tube 31 and to suppress the thermal stress and the thermal fatigue of the heat transfer tube 31.

  Further, after the air bubbles (ie, combustion gas) are accumulated on the lower surface of the baffle plate 152 having an arc-shaped cross section and having an upwardly convex shape, the air bubbles B overflowing from the side edge of the baffle plate 152 rise. The heat transfer tube 31 is reached. Here, since the bubble injection holes 151 are provided in the upper surface portion of the sparge pipe 15, as described above, the base end portion of the sparge pipe 15 has a relatively large amount of bubble injection, and the tip end portion has a relative bubble injection amount. Will be reduced. However, by configuring the gas to be stored on the lower surface of the baffle plate 152 interposed between the sparge pipe 15 and the heat transfer pipe 31, the ejection amount of the air bubbles B ejected from the sparge pipe 15 is uneven in the longitudinal direction. Also, the supply amount of the air bubbles B supplied from the baffle plate 152 to the heat transfer tubes 31 can be made substantially uniform in the longitudinal direction. Therefore, also in the air bubble ejection mechanism 101, it is possible to suppress the thermal stress and thermal fatigue of the heat transfer tube 31 located above the base end portion of the sparge pipe 15.

  In the configuration example shown in FIG. 8 and the like, the baffle plate 152 having a circular arc shape in cross section is illustrated, but the shape of the baffle plate is not limited to this. Although illustration is omitted, for example, a baffle plate having an inverted V-shaped cross section may be employed. Moreover, if only the function of diverting the air bubbles B is obtained, it is also possible to adopt a flat baffle plate.

  Further, in the configuration example shown in FIG. 8 etc., the bubble ejection holes 151 are formed in the upper surface portion of the sparge pipe 15, but in the bubble ejection mechanism 101 having the baffle plate 152, the sparge pipe is the same as the configuration example shown in FIG. The air bubble injection hole 151 may be formed in the lower surface portion 15 of FIG. That is, the formation of the air bubble injection hole 151 in the lower surface portion of the sparge pipe 15 may be combined with the baffle plate 152.

  Furthermore, the diameters of the bubble injection holes 151 may not be all the same, but may be changed according to the longitudinal position of the sparge pipe 15. For example, the diameter of the air bubble injection hole 151 provided at the base end of the sparge pipe 15 may be relatively small, and the diameter of the air bubble injection hole 151 provided at the tip of the sparge pipe 15 may be relatively large. This prevents the bubble ejection amount from becoming uneven in the longitudinal direction of the sparge pipe 15.

  In addition, depending on the position of the sparge pipe 15 in the longitudinal direction, the angle of the hole axis of the bubble injection hole 151 with respect to the vertically upper side may be changed. For example, as shown in FIG. 7, the air bubble injection hole 151 provided at the base end of the sparge pipe 15 makes the angle of the hole axis relatively large, and the air bubble injection hole 151 provided at the tip of the sparge pipe 15 is the hole axis. The angle may be relatively small. This prevents the bubble ejection amount from becoming uneven in the longitudinal direction of the sparge pipe 15.

  As a modification, as shown in FIG. 11, the baffle plate 153 may be disposed only above the base end of the sparge pipe 15. As a result, at the base end of the sparge pipe 15, the rising air bubbles are blocked by the baffle plate 153. Although the base end of the sparge pipe 15 tends to have a relatively large amount of bubble ejection, suppressing the thermal stress and thermal fatigue of the heat transfer tube 31 located above the base end of the sparge pipe 15 by the baffle plate 153 Becomes possible.

  In the example of FIG. 11, the baffle plate 153 is provided at the base end when the portion where the bubble injection hole 151 of the sparge pipe 15 is formed is divided into three of the tip end portion, the middle portion and the base end portion. Although the above configuration is shown as an example, the range in which the baffle plate 153 is disposed in the longitudinal direction of the sparge pipe 15 can be set as appropriate.

  Further, in the configuration example shown in FIG. 11, the air bubble injection holes 151 formed in the sparge pipe 15 are, like the configuration example shown in FIG. Alternatively, as in the configuration example shown in FIG. 7, the angle of the hole axis of the air bubble injection hole 151 with respect to the vertically upward direction may be changed according to the position in the longitudinal direction of the sparge pipe 15.

  In the configuration example shown in FIG. 8 and the like, the baffle plates 152 and 153 are disposed on the side closer to the sparge pipe 15 between the sparge pipe 15 and the heat transfer pipe 31, but the baffle plates 152 and 153 are transmitted. It may be disposed on the side close to the heat pipe 31. For example, the baffle plates 152 and 153 may be disposed immediately below the heat transfer tube 31. The baffle plates 152 and 153 disposed immediately below the heat transfer tube 31 may be provided along the heat transfer tube 31. This configuration is advantageous in reliably preventing the air bubbles and the surrounding water from vigorously colliding with the heat transfer tube 31.

  In addition, one or more through holes may be formed in the baffle plates 152, 153. By doing this, some of the air bubbles blocked by the baffle plates 152, 153 will pass through the through holes of the baffle plates 152, 153, but at that time the rising speed will be reduced and the air bubbles will be And the surrounding water is prevented from vigorously colliding with the heat transfer tube 31. Also, if the diameter of the through holes is made relatively small so that the size of the air bubbles after passing through the through holes of the baffle plates 152, 153 will be small, the air bubbles will become In the meantime, heat exchange between air bubbles and water is promoted. As a result, it is possible to reduce the temperature of the air bubbles when reaching the heat transfer tube. Preferably, at least a part of the air bubbles form through holes so as to bypass the baffle plates 152 and 153.

  Furthermore, although illustration is omitted, the baffle plate makes the configuration and / or arrangement of the baffle plate disposed on the proximal end side of the sparge pipe 15 different from the configuration and / or arrangement of the baffle plate disposed on the distal end side of the sparge pipe 15 You may do so. For example, the sizes of the baffle plate disposed on the proximal end side of the sparge pipe 15 and the baffle plate disposed on the distal end side may be different from each other. Further, the height position of the baffle plate disposed on the proximal end side of the sparge pipe 15 may be different from the height position of the baffle plate disposed on the distal end side. When a curved baffle plate is used, the curvatures of curvature of the baffle plate disposed on the proximal end side of the sparge pipe 15 and the baffle plate disposed on the distal end side may be different from each other. Furthermore, in the case where the through holes are provided in the baffle plate, the number, size, etc. of through holes in the baffle plate disposed on the base end side of the sparge pipe 15 and the baffle plate disposed on the distal end side differ from each other. Good.

  The technology disclosed herein can also be applied to an intermediate heat medium type vaporizer such as a steam ejector vaporizer having a sparge pipe disposed in a water tank.

1 Underwater combustion type vaporization device (vaporization device)
11 water tank 15 sparge pipe 100 bubble ejection mechanism 101 bubble ejection mechanism 110 cold water region 151 bubble ejection holes 152, 153 baffle plate 31 heat transfer tube 32 heat exchanger

Claims (10)

A bubble injection mechanism having a plurality of sparge pipes immersed in the water tank and having a plurality of bubble injection holes formed on the circumferential surface, and configured to eject a high temperature gas into water through the bubble injection holes;
Heat exchange disposed above the bubble jetting mechanism in the water tank and configured to vaporize low temperature liquefied gas flowing inside the heat transfer tube by stirring and heating of water by the bubbles jetted from the sparge pipe Equipped with
Each of the plurality of sparge pipes is disposed extending in a predetermined direction from the proximal end which is the inflow end of the high-temperature gas, and its distal end is closed,
The bubble injection mechanism has a baffle plate interposed between the sparge pipe and the heat transfer pipe, and diverts the air bubbles ejected from the bubble injection holes of at least a part of the sparge pipe to the baffle plate. While, the low temperature liquefied gas vaporization device configured to reach the heat transfer tube of the heat exchanger. In the vaporizer for low temperature liquefied gas according to claim 1,
A vaporization device for low-temperature liquefied gas, wherein at least a part of the bubble jet holes formed on the circumferential surface of the sparge pipe is a bypass bubble jet hole provided so that the hole axis is lower than horizontal. In the vaporizer for low temperature liquefied gas according to claim 2,
The bypass bubble injection hole is a vaporization device of low-temperature liquefied gas provided at a base end of the sparge pipe. In the vaporizer for low temperature liquefied gas according to claim 2 or 3,
The bypass bubble injection hole is a vaporization device for low-temperature liquefied gas provided from the proximal end to the distal end of the sparge pipe. The low temperature liquefied gas vaporizer according to claim 3 or 4
The hole axis of the bypass bubble injection hole provided at the base end of the sparge pipe has an angle with respect to the vertically upward direction larger than the angle of the hole axis of the air bubble injection hole provided at the tip of the sparge pipe Low temperature liquefied gas vaporizer. In the vaporization device for low temperature liquefied gas according to any one of claims 2 to 5,
Under the sparge pipe, a low temperature liquefied gas vaporization device is provided with a cold water zone. In the vaporizer for low temperature liquefied gas according to any one of claims 1 to 6 ,
The baffle plate is a device for evaporating low temperature liquefied gas disposed at a proximal end of the sparge pipe. In the vaporization device for low temperature liquefied gas according to any one of claims 1 to 7 ,
The baffle plate is disposed from the proximal end to the distal end of the sparge pipe. The vaporization device for low temperature liquefied gas according to any one of claims 1 to 8 ,
The said baffle plate is a vaporization apparatus of the low temperature liquefied gas arrange | positioned by the side of the said heat transfer pipe between the said sparge pipe and the said heat transfer pipe. The vaporization device for low temperature liquefied gas according to any one of claims 1 to 9 ,
The baffle plate has a through hole provided therein.

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