JP6839975B2 - Intermediate medium vaporizer - Google Patents

Description

The present invention relates to an intermediate medium vaporizer.

Conventionally, as disclosed in Patent Document 1 below, as an apparatus for vaporizing a low-temperature liquid such as LNG, an intermediate medium type vaporizer using an intermediate medium in addition to a heat source fluid is known. As shown in FIG. 10, the intermediate medium type vaporizer disclosed in Patent Document 1 includes an intermediate medium evaporator 81, an LNG evaporator 82, and a warmer 83. Further, the intermediate medium type vaporizer is provided with an inlet chamber 85, a large number of heat transfer tubes 86, an intermediate chamber 87, a large number of heat transfer tubes 88 and an outlet chamber 89 in this order as a path through which seawater as a heat source fluid passes. Has been done. The heat transfer tube 86 is arranged in the warmer 83, and the heat transfer tube 88 is arranged in the intermediate medium evaporator 81. An intermediate medium (for example, propane) having a boiling point lower than the temperature of seawater is housed in the intermediate medium evaporator 81.

The LNG evaporator 82 includes an inlet chamber 91 and an outlet chamber 92, and a large number of heat transfer tubes 93 that communicate the both chambers 91 and 92. Each heat transfer tube 93 has a substantially U shape and protrudes from the upper part in the intermediate medium evaporator 81. The outlet chamber 92 communicates with the warmer 83 via the NG conduit 94.

In such a vaporizer, seawater, which is a heat source fluid, reaches the outlet chamber 89 through the inlet chamber 85, the heat transfer tube 86, the intermediate chamber 87, and the heat transfer tube 88. At this time, the seawater passing through the heat transfer tube 88 exchanges heat with the liquid intermediate medium M in the intermediate medium evaporator 81 to evaporate the intermediate medium M.

On the other hand, the LNG to be vaporized is introduced into the heat transfer tube 93 from the inlet chamber 91. By heat exchange between the LNG in the heat transfer tube 93 and the evaporation intermediate medium in the intermediate medium evaporator 81, the intermediate medium M is condensed, and LNG evaporates in the heat transfer tube 93 in response to the heat of condensation, resulting in NG. It becomes. This NG is introduced into the warmer 83 from the outlet chamber 92 through the NG conduit 94, further heated by heat exchange with the seawater flowing through the heat transfer tube 86 in the warmer 83, and then supplied to the user side. To.

Japanese Unexamined Patent Publication No. 2000-227200

In the intermediate medium type vaporizer disclosed in Patent Document 1, the LNG evaporator 82 has a configuration having a large number of heat transfer tubes 93. Therefore, the LNG evaporator 82 becomes considerably heavy.

Therefore, the present invention has been made in view of the above-mentioned prior art, and an object of the present invention is to reduce the weight of the intermediate medium type vaporizer.

In order to achieve the above object, the present invention has a shell in which an intermediate medium is housed, and at least a part of the intermediate medium is exchanged by heat exchange between the heat source medium and the liquid intermediate medium in the shell. The liquefied gas vaporization unit includes an intermediate medium vaporization unit for evaporating and a liquefied gas vaporization unit for vaporizing the low-temperature liquefied gas and causing the gas to flow out by condensing the intermediate medium evaporated in the intermediate medium evaporation unit. , A laminated body in which a first flow path layer having a plurality of first flow paths, which is a flow path of an intermediate medium, and a second flow path layer having a plurality of second flow paths, which are flow paths of a low-temperature liquefied gas, are laminated. is constituted by a laminated heat exchanger having the stacked heat exchanger is disposed in the intermediate medium evaporating unit within said shell Rutotomoni, upper portion of the plurality of first flow path in each of the shell open and the laminated heat exchanger, flowing into the plurality of first flow path from said plurality of first flow path in each of an upper end portion and the intermediate medium evaporating portion and the shell through the opening of the an intermediate medium wherein the first flow path to so that to the outflow flows down by gravity from said first flow path, a direction in which the first flow path is inclined with respect to the attitude or the vertical direction extending downward from the upper portion It is an intermediate medium type vaporizer installed in a posture extending to.

In this intermediate medium type vaporizer, since the liquefied gas vaporizer is composed of a laminated heat exchanger, the liquefied gas vaporizer is compared with the case where the liquefied gas vaporizer is formed by a multi-tube heat exchanger. The part can be made smaller and lighter. Moreover, since the laminated heat exchanger is configured so that the intermediate medium flows down in the first flow path by gravity, the laminated heat exchanger accompanies the condensation of the intermediate medium in the first flow path. As the pressure in the first flow path decreases, the gaseous intermediate medium easily flows into the first flow path. Therefore, even when the liquefied gas vaporization unit is composed of a laminated heat exchanger having a laminated body in which the first flow path and the second flow path are formed, the intermediate medium is pushed into the first flow path. There is no need to provide means. From this point as well, the weight of the intermediate medium type vaporizer can be reduced.
Further, the intermediate medium circulates in the shell between the intermediate medium evaporation section and the liquefied gas vaporization section. Therefore, the flow resistance until the intermediate medium evaporated in the intermediate medium evaporation section is sucked into the first flow path can be reduced. Therefore, it is possible to facilitate natural circulation.

The liquefied gas vaporization unit may be provided with a liquid reservoir in which a liquid intermediate medium is accumulated on the downstream side of the first flow path.

In this aspect, it is possible to prevent the gas intermediate medium from flowing into the first flow path from the downstream end of the first flow path. Therefore, since the intermediate medium flows into the first flow path from one direction, the formation of a downward flow of the intermediate medium in the first flow path is promoted. Therefore, the intermediate medium can be easily circulated between the intermediate medium evaporation section and the liquefied gas vaporization section.

The intermediate medium evaporation section may be located below the liquefied gas vaporization section. In this case, the intermediate medium type vaporizer may further include a liquid sealing tube that connects the liquid reservoir and the liquid level of the liquid intermediate medium accumulated in the intermediate medium evaporation section.

In this embodiment, the liquid sealing tube is filled with a liquid intermediate medium, and the liquid intermediate medium stored in the liquid reservoir and the liquid intermediate medium collected in the intermediate medium evaporation portion are connected through the liquid sealing tube. .. Then, when the pressure in the first flow path drops as the intermediate medium condenses in the first flow path, the liquid level of the liquid intermediate medium stored in the liquid reservoir and the evaporation part of the intermediate medium are reached. The head (differential pressure) corresponding to the difference in height from the liquid level of the accumulated liquid intermediate medium acts as an inflow suction force of the intermediate medium into the first flow path. At this time, since the distance between the liquid level in the liquid reservoir and the liquid level in the intermediate medium evaporation portion can be increased according to the length of the liquid sealing tube, the first flow path according to this distance. The suction force inward can be increased. Further, since the liquid level in the liquid reservoir and the liquid level in the intermediate medium evaporation section are connected by the liquid sealing tube, the liquid level in the intermediate medium evaporation section is intermediate as compared with the case where the liquid reservoir directly contacts the liquid level in the intermediate medium evaporation section. It is possible to suppress the reduction of the evaporation surface of the medium.

The laminated heat exchanger may be a microchannel heat exchanger. In this aspect, the liquefied gas vaporization unit can be miniaturized and lightened. Here, the microchannel heat exchanger is a heat exchanger provided with a laminated body formed by laminating a large number of metal plates having excellent heat transfer characteristics. In this laminated body, a flow path layer made of a metal plate in which a flow path through which an intermediate medium flows is recessed and a flow path layer made of a metal plate in which a flow path through which a low-temperature liquefied gas flows are recessed are alternately laminated. It has a structure like this. The flow path formed in these metal plates has, for example, a flow path width of 0.2 mm to 3 mm.

As described above, according to the present invention, it is possible to reduce the weight of the intermediate medium type vaporizer.

It is a figure which shows schematic structure of the intermediate medium type vaporizer which concerns on 1st Embodiment of this invention. It is a figure which shows schematic structure of the LNG evaporator provided in the said intermediate medium type vaporizer. It is a figure which shows typically the structure of the laminated type heat exchanger which comprises the warmer provided in the said intermediate medium type vaporizer. It is a figure which shows schematic structure of the intermediate medium type vaporizer which concerns on the modification of 1st Embodiment of this invention. It is a figure which shows schematic structure of the intermediate medium type vaporizer which concerns on the modification of 1st Embodiment of this invention. It is a figure which shows schematic structure of the intermediate medium type vaporizer which concerns on the modification of 1st Embodiment of this invention. It is a figure which shows schematic structure of the intermediate medium type vaporizer which concerns on the modification of 1st Embodiment of this invention. It is a figure which shows schematic structure of the intermediate medium type vaporizer which concerns on 2nd Embodiment of this invention. It is a figure which shows schematic structure of the intermediate medium type vaporizer which concerns on the modification of 2nd Embodiment of this invention. It is a figure which shows roughly the structure of the conventional intermediate medium type vaporizer.

Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings.

(First Embodiment)
As shown in FIG. 1, the intermediate medium type vaporizer (hereinafter, simply referred to as a vaporizer) 10 according to the first embodiment uses the heat of seawater as a heat source medium as a low-temperature liquefied gas via the intermediate medium M. It is a device that obtains NG (natural gas) by transmitting it to LNG (liquefied natural gas) and vaporizing LNG. As the intermediate medium M, for example, propane or the like can be used. The vaporizer 10 may be configured as a device for vaporizing or heating a low-temperature liquefied gas other than LNG, such as liquefied petroleum gas (LPG) and liquid nitrogen (LN _2).

The vaporizer 10 includes an intermediate medium evaporator E1 which is an intermediate medium evaporator, an LNG evaporator E2 which is a liquefied gas vaporizer, and a warmer E3. The LNG evaporator E2 is arranged in the shell 11 of the intermediate medium evaporator E2. Further, the warmer E3 is arranged on the side of the shell 11. An intermediate chamber 14 is formed between the shell 11 and the warmer E3.

The shell 11 has a shape that is long in the horizontal direction. A large number of heat transfer tubes 20 of the intermediate medium evaporator E1 are arranged in the lower part of the shell 11. The LNG evaporator E2 is arranged in the upper part of the shell 11.

An intermediate chamber 14 is adjacent to one of the pair of side walls constituting the shell 11 of the intermediate medium evaporator E1, and an outlet chamber 18 is adjacent to the other. The heat transfer tube 20 is arranged at the lower part of the space in the shell 11. The heat transfer tube 20 includes a first side wall 11a that functions as a partition wall between the intermediate chamber 14 and the inside of the shell 11, and an outlet chamber 18 and a shell among a pair of side walls facing each other that form the shell 11 of the intermediate medium evaporator E1. It is bridged between the second side wall 11b which functions as a partition wall from the inside of the eleven. The heat transfer tube 20 has a shape extending linearly in one direction, but is not limited to this shape. The inside of the heat transfer tube 20 communicates with the intermediate chamber 14 and the outlet chamber 18.

A discharge pipe 24 for discharging seawater is connected to the outlet chamber 18. The seawater in the outlet chamber 18 is discharged to the outside through the discharge pipe 24.

An intermediate medium (for example, propane) M having a boiling point lower than the temperature of seawater is housed in the shell 11. The intermediate medium M is accommodated to such an extent that the liquid level is located above all the heat transfer tubes (heat source fluids, for example, heat transfer tubes through which seawater flows) 20.

Above the exit chamber 18, an LNG inlet chamber 26 and an exit chamber 28 for deriving NG are provided. A supply pipe 30 for introducing LNG is connected to the entrance chamber 26. A lead-out pipe 32 for leading out NG is connected to the outlet chamber 28. In FIG. 1, the outlet chamber 28 is drawn for convenience so as to be located above the inlet chamber 26, but in reality, the outlet chamber 28 and the inlet chamber 26 are of the microchannel heat exchanger described later. Depending on the configuration, they are lined up side by side. However, the configuration is not limited to this.

As shown in FIG. 2, the LNG evaporator E2 is composed of a microchannel heat exchanger which is an example of a laminated heat exchanger having a laminated body 38 in which a first flow path 41a and a second flow path 42a are formed. Has been done. Specifically, the microchannel heat exchanger has a configuration in which a laminated body 38 of flow path layers 41 and 42 made of a metal plate is sandwiched between the end plates 43 and 43. The laminated body 38 has a first flow path layer 41 in which a large number of flow paths (first flow path) 41a through which the intermediate medium M flows are recessed, and a large number of flow paths (second flow path) 42a through which LNG flows. The recessed second flow path layer 42 is alternately laminated. Then, heat exchange is performed between the intermediate medium M flowing through each of the first flow paths 41a and the LNG flowing through each of the second flow paths 42a, and the LNG is vaporized by being heated.

Both the first flow path layer 41 and the second flow path layer 42 are in a vertical posture and extend in a direction (horizontal direction) parallel to the extending direction of the heat transfer tube 20 of the intermediate medium evaporator E1. However, the flow path layers 41 and 42 are not limited to the vertical posture, and may be in an inclined posture. Further, the flow path layers 41 and 42 may be in a posture extending in a direction intersecting with the extending direction of the heat transfer tube 20 and not parallel to the extending direction.

Each of the first flow paths 41a is formed so as to extend in the vertical direction, and is arranged so as to be arranged in the longitudinal direction of the first flow path layer 41. No header is provided on the upper side of the laminate 38. Therefore, the upper end of the first flow path 41a is open to the inside of the shell 11. Therefore, the gaseous intermediate medium M in the shell 11 directly flows into the first flow path 41a without passing through the header.

The first flow path 41a is not limited to a configuration extending in the vertical direction, and may be formed in a shape extending in a direction inclined from the vertical direction. Further, the first flow path 41a is not limited to a shape extending linearly, and may be configured to bend or meander in the middle. In short, the first flow path 41a may be configured such that the intermediate medium M flows down from the inflow end to the outflow end in the first flow path 41a by gravity and flows out from the outflow end.

A liquid reservoir 45 is provided on the lower side of the laminated body 38. The liquid reservoir 45 stores the intermediate medium M condensed in the first flow path 41a, and is directly bonded to the lower end portion of the laminated body 38. The liquid reservoir 45 is formed in a shape that covers the entire lower surface of the laminated body 38 so that its internal space communicates with all the first flow paths 41a. That is, the liquid intermediate medium M is stored on the downstream side of the first flow path 41a. The lower part of the first flow path 41a is blocked by the liquid intermediate medium M stored in the liquid reservoir 45. A gas layer may be present between the liquid intermediate medium M accumulated in the lower end portion of the first flow path 41a and the liquid intermediate medium M accumulated in the liquid reservoir 45, or The gas layer does not have to be present. This will change depending on the driving situation. In any state, since the liquid intermediate medium M is stored under the first flow path 41a, the gaseous intermediate medium M is sucked from the lower side of the first flow path 41a. Is prevented.

A liquid sealing pipe 46 is connected to the bottom surface of the liquid reservoir 45. The liquid sealing tube 46 extends downward from the bottom surface of the liquid reservoir 45. The lower end of the liquid sealing tube 46 is immersed in the intermediate medium M stored in the intermediate medium evaporator E1. More specifically, the lower end of the liquid sealing tube 46 is immersed in the intermediate medium M and is arranged above each heat transfer tube 20 of the intermediate medium evaporator E1. That is, the liquid sealing tube 46 connects the lower part of the LNG evaporator E2 and the upper part of the intermediate medium evaporator E1. Therefore, the bottom surface of the liquid reservoir 45 is arranged at a position separated above the liquid surface of the intermediate medium M stored in the intermediate medium evaporator E1. Therefore, the LNG evaporator E2 is located above the liquid level of the intermediate medium evaporator E1.

The inside of the liquid reservoir 45 and the inside of the liquid sealing tube 46 are filled with the liquid intermediate medium M. In other words, the liquid sealing pipe 46 connects the liquid intermediate medium M in the liquid reservoir 45 and the liquid level of the liquid intermediate medium M accumulated in the intermediate medium evaporator E1. The liquid sealing tube 46 has a cross-sectional area sufficiently smaller than the area of the bottom surface of the liquid reservoir 45.

Each of the second flow paths 42a is formed so as to extend in a direction orthogonal to the first flow path 41a, specifically, in the longitudinal direction of the second flow path layer 42, and is arranged so as to be arranged vertically. .. The second flow path 42a is not limited to a shape that extends straight, and may be bent or meandering in the middle.

The flow paths 41a and 42a are formed by, for example, etching the metal plates 41 and 42, and have a groove shape having a semicircular cross section, for example. The flow paths 41a and 42a have, for example, a flow path width of 0.2 mm to 3 mm.

In the present embodiment, two sets of laminated bodies 38 of the flow path layers 41 and 42 sandwiched between the end plates 43 and 43 are provided. Then, in one set, LNG flows from the front to the back of FIG. 2, and in the other set, LNG after flowing through one set flows from the back to the front of FIG. That is, in this embodiment, it has a two-pass configuration. The liquid reservoir 45 is formed in a size that communicates with the first flow path 41a of both paths. Instead of this configuration, the liquid reservoir 45 has a first liquid reservoir connected to the first flow path 41a in the laminated body 38 forming the first path and a first liquid reservoir 45 in the laminated body 38 forming the second path. A configuration may be configured in which a second liquid reservoir connected to one flow path 41a is separately provided. In this case, the liquid sealing pipe 46 is configured to include a first liquid sealing pipe connected to the first liquid reservoir and a second liquid sealing pipe connected to the second liquid reservoir.

Headers are provided on the back side and the front side of FIG. 2 (see FIG. 1). In FIG. 2, for convenience, the headers on the front side (distribution header 48 and set header 50) are omitted. As headers, a distribution header 48 (see FIG. 1) that distributes LNG introduced through the inlet chamber 26 to each second flow path 42a and each second flow path 42a in the first set of laminated bodies 38 flowed. Along with assembling the LNG, the connection header 49 that is distributed to each second flow path 42a in the second set of laminated bodies 38 and the NG that has flowed through each second flow path 42a in the second set of laminated bodies 38 are assembled. A set header 50 (see FIG. 1) that is allowed to lead to the exit chamber 28 is provided. In FIG. 1, for convenience, the distribution header 48 and the set header 50 are drawn so as to be arranged vertically, but in reality, they are arranged side by side.

In the present embodiment, the microchannel heat exchanger (LNG evaporator E2) has a configuration having two passes, but the present invention is not limited to this, and the microchannel heat exchanger (LNG evaporator E2) has a configuration having one pass or three or more passes. May be good. Further, the laminated heat exchanger (LNG evaporator E2) is not limited to the case where it is composed of a microchannel heat exchanger. For example, a large number of metal plates formed in a corrugated manner may be laminated, and a space between adjacent metal plates may be formed by a plate fin heat exchanger formed as a first flow path and a second flow path. ..

Return to FIG. A warmer E3 is connected to the outlet pipe 32. The housing 52 of the warmer E3 forms an intermediate chamber 14 with the shell 11. On the side wall of the housing 52 opposite to the shell 11, for example, a seawater inlet chamber 53, which is a heat source medium, is provided. For example, seawater, which is a heat source medium, is introduced into the inlet chamber 53.

In the housing 52, a large number of heat transfer tubes 54 (heat transfer tube type heat exchanger E3b) through which, for example, seawater, which is a heat source medium, and a laminated heat exchanger E3a in which NG is introduced from the lead-out tube 32 are arranged. It is installed. Further, the intermediate medium M2 is enclosed in the housing 52 of the warmer E3. The intermediate medium M2 is composed of, for example, propane. The heat transfer tube 54 is bridged between the side wall adjacent to the intermediate chamber 14 and the side wall adjacent to the inlet chamber 53. The heat transfer tube 54 is arranged below the liquid level of the liquid intermediate medium M2 stored in the housing 52, and the laminated heat exchanger E3a is arranged above the liquid level.

In the present embodiment, the laminated heat exchanger E3a of the warmer E3 is configured by a microchannel heat exchanger, and has the same configuration as the LNG evaporator E2. Therefore, as shown in FIG. 3, the laminated heat exchanger E3a in the warmer E3 also has the first flow path layer 56 in which the first flow path 56a through which the intermediate medium M2 flows is formed and the first flow path layer 56 through which the LN flows. A laminate with the second flow path layer 57 in which two flow paths (not shown) are formed is provided between the end plates 58 and 58. The upper end of the first flow path 56a is open to the upper surface of the laminated body. The second flow path extends in a direction orthogonal to the first flow path 56a.

The laminated heat exchanger E3a is provided with headers 61 and 62 on a pair of side surfaces facing opposite sides. For example, the header on the front side shown in FIG. 3 is the inflow side header 61 connected to the lead-out pipe 32. On the side opposite to the inflow side header 61, an outflow side header 62 for collecting and flowing out NG flowing through the second flow path is provided. In the present embodiment, since the configuration is one pass, the headers 61 and 62 are divided into front and rear side surfaces. However, the configuration is not limited to one pass, and may have two or more passes.

Like the LNG evaporator E2, the laminated heat exchanger E3a is provided with a liquid reservoir 59 and a liquid sealing tube 63. The liquid reservoir 59 is provided on the lower side of the laminated body, and the liquid sealing pipe 63 is connected to the bottom surface of the liquid reservoir 59. The liquid reservoir 59 is formed in a shape that covers the entire lower surface of the laminated body so that its internal space communicates with all the first flow paths 56a. The liquid intermediate medium M2 stored in the liquid reservoir 59 closes below the lower end of the first flow path 56a. The liquid sealing tube 63 extends downward from the bottom surface of the liquid reservoir 59. The lower end of the liquid sealing tube 63 is immersed in the intermediate medium M2 stored in the housing 52. A gas layer may be present between the liquid intermediate medium M2 accumulated in the lower end portion of the first flow path 56a and the liquid intermediate medium M2 accumulated in the liquid reservoir 59, or The gas layer does not have to be present.

The NG flows into the inflow side header 61 through the outlet pipe 32, and is diverted to each second flow path through the inflow side header 61. The NG in each second flow path is heated by the intermediate medium M2 of the first flow path 56a. This NG flows into the outflow side header 62, and is then supplied to the user side through the discharge pipe 65.

Here, the operation operation of the vaporizer 10 according to the first embodiment will be described.

The liquid intermediate medium M stored in the lower part of the shell 11 is heated by the seawater that has flowed into each heat transfer tube 20 through the intermediate chamber 14 and evaporates. The seawater flows out from the heat transfer pipe 20 and is discharged to the outside through the outlet chamber 18 and the discharge pipe 24.

The evaporated intermediate medium M exchanges heat with LNG in the LNG evaporator E2 located at the upper part in the shell 11. Specifically, in the LNG evaporator E2, heat exchange is performed between the intermediate medium M in the first flow path 41a and the LNG in the second flow path 42a, and the gaseous intermediate medium M is condensed. , LNG evaporates. At this time, due to the condensation of the intermediate medium M, the pressure in the first flow path 41a becomes lower than the pressure around the microchannel heat exchanger. Since the lower side of the first flow path 41a below the lower end is blocked by the liquid intermediate medium M stored in the liquid reservoir 45 and the liquid sealing pipe 46, the liquid intermediate medium M is stored in the liquid reservoir 45 and the liquid sealing pipe 46. The head (differential pressure) corresponding to the difference in height between the liquid level of the liquid intermediate medium and the liquid level of the liquid intermediate medium accumulated in the intermediate medium evaporator E1 is intermediate in the first flow path 41a. It acts as an inflow suction force of the medium. Therefore, the gaseous intermediate medium M is sucked into the first flow path 41a through the opening at the upper end of the first flow path 41a, and is not sucked from the lower end of the first flow path 41a. As a result, a flow in the direction in which the intermediate medium M flows down is generated in the first flow path 41a. The intermediate medium M flowing down the first flow path 41a is stored in the liquid reservoir 45. In this way, in the shell 11, the circulation of the intermediate medium M is repeated between the intermediate medium evaporator E1 and the LNG evaporator E2.

The NG vaporized by the LNG evaporator E2 flows through the outlet pipe 32 via the outlet chamber 28 and is introduced into the warmer E3. In the warmer E3, the heat exchanger E3 flows into the second flow path of the laminated heat exchanger E3a from the outlet pipe 32 through the inflow side header 61. The NG in the second flow path is heated by the intermediate medium M2 flowing in the first flow path 56a and is supplied to the utilization side via the outflow side header 62 and the discharge pipe 65.

Also in the warmer E3, the intermediate medium M2 flows down from the top to the bottom in the first flow path 56a of the laminated heat exchanger E3a. That is, also in the laminated heat exchanger E3a of the warmer E3, as in the LNG evaporator E2, the liquid level of the liquid intermediate medium M2 stored in the liquid reservoir 59 is intermediate between the liquid level collected in the housing 52. The head (differential pressure) corresponding to the difference in height of the medium M2 from the liquid level acts as an inflow attraction force of the intermediate medium M2 into the first flow path 56a.

As described above, in the present embodiment, since the LNG evaporator E2 includes a laminated heat exchanger, the LNG evaporator E2 is formed by a multi-tube heat exchanger as compared with the case where the LNG evaporator E2 is formed by a multi-tube heat exchanger. The evaporator E2 can be made smaller and lighter. Moreover, since the laminated heat exchanger is configured so that the intermediate medium M flows down in the first flow path 41a by gravity, the intermediate medium M is condensed in the first flow path 41a in the laminated heat exchanger. As a result, the pressure in the first flow path 41a decreases, so that the gaseous intermediate medium M easily flows into the first flow path 41a. Therefore, even when the LNG evaporator E2 is composed of a laminated heat exchanger having a laminated body 38 in which the first flow path 41a and the second flow path 42a are formed, an intermediate medium is contained in the first flow path 41a. It is not necessary to provide a means for pushing M.

Moreover, in the present embodiment, since the LNG evaporator E2 is provided with the liquid reservoir 45, the lower part of the first flow path 41a below the lower end is closed with the liquid intermediate medium M. Therefore, it is possible to prevent the intermediate medium M from flowing into the first flow path 41a from the downstream end portion. Therefore, since the intermediate medium M flows into the first flow path 41a from one direction, it becomes easy to obtain the flow of the intermediate medium M in the first flow path 41a. Therefore, the intermediate medium M can be easily circulated between the intermediate medium evaporator E1 and the LNG evaporator E2.

Further, in the present embodiment, a liquid sealing pipe 46 is provided for connecting the liquid reservoir 45 and the liquid level of the liquid intermediate medium M accumulated in the intermediate medium evaporator E1, and the liquid intermediate medium M is filled in the liquid sealing pipe 46. Has been done. Therefore, the liquid intermediate medium M stored in the liquid reservoir 45 and the liquid intermediate medium M stored in the intermediate medium evaporator E1 are connected to each other through the liquid sealing pipe 46. Then, when the pressure in the first flow path 41a drops as the intermediate medium M condenses in the first flow path 41a, the liquid level of the liquid intermediate medium M stored in the liquid reservoir 45 becomes The head (differential pressure) corresponding to the difference in height of the liquid intermediate medium M accumulated in the intermediate medium evaporator E1 from the liquid level acts as an inflow suction force of the intermediate medium M into the first flow path 41a. .. At this time, since the distance between the liquid level in the liquid reservoir 45 and the liquid level in the intermediate medium evaporator E1 can be increased according to the length of the liquid sealing tube 46, the distance between the liquid level and the liquid level in the intermediate medium evaporator E1 can be increased. The suction force into one flow path 41a can be further increased. Further, since the liquid sealing tube 46 is connected to the liquid level in the intermediate medium evaporator E1, it is possible to suppress the decrease in the evaporation surface of the intermediate medium M as compared with the case where the liquid reservoir 45 is directly connected to the liquid level. be able to.

Further, in the present embodiment, the LNG evaporator E2 is arranged in the shell 11 of the intermediate medium evaporator E1. Therefore, the intermediate medium M circulates in the shell 11 between the intermediate medium evaporator E1 and the LNG evaporator E2. Therefore, the flow resistance until the intermediate medium M vaporized by the intermediate medium evaporator E1 is sucked into the first flow path 41a can be reduced. Therefore, it is possible to facilitate natural circulation.

Further, in the present embodiment, the laminated heat exchanger of the LNG evaporator E2 is a microchannel heat exchanger. Therefore, the LNG evaporator E2 can be made smaller and lighter.

In the above embodiment, the configuration in which the liquid reservoir 45 and the liquid sealing tube 46 are provided has been described, but as shown in FIG. 4, the liquid reservoir 45 and the liquid sealing tube 46 are omitted, and the LNG evaporator E2 is used as an intermediate medium. It may be arranged above the liquid level of M. Alternatively, as shown in FIG. 5, only the liquid sealing tube 46 may be omitted, and the LNG evaporator E2 and the liquid reservoir 45 may be arranged above the liquid level of the intermediate medium M.

Further, as shown in FIG. 6, the liquid sealing pipe 46 may be omitted, and the liquid reservoir 45 may be in direct contact with the intermediate medium M stored in the intermediate medium evaporator E1. In this configuration, the intermediate medium M in the liquid reservoir 45 and the intermediate medium M accumulated in the intermediate medium evaporator E1 are connected to each other through the opening formed in the liquid reservoir 45. Therefore, even in this form, the difference in height between the liquid level of the liquid intermediate medium M stored in the liquid reservoir 45 and the liquid level of the liquid intermediate medium M stored in the intermediate medium evaporator E1 does not become large. The suction force of the intermediate medium M corresponding to the head (differential pressure) corresponding to the difference can be obtained.

Further, the liquid sealing tube 63 provided in the laminated heat exchanger E3a in the warmer E3 can be omitted in the same manner, and the liquid reservoir 59 in the warmer E3 is also directly in the warmer E3. It can be immersed in the liquid surface of the intermediate medium M2. Further, the liquid reservoir 59 may be omitted.

In the above embodiment, the warmer E3 is configured as an intermediate medium type heat exchanger, and the laminated heat exchanger E3a is provided, but the present invention is not limited to this. For example, as shown in FIG. 7, the laminated heat exchanger E3a is omitted, and NG introduced into the housing 52 of the warmer E3 through the lead-out pipe 32 and heat source medium such as seawater flowing in the heat transfer pipe. May be configured to directly exchange heat. In this configuration, the warmer E3 is configured as a multi-tube heat exchanger in which the inside of the housing 52 is filled with NG and a heat transfer tube is arranged therein.

Further, in the above-described embodiment, the warmer E3 is provided, but the warmer E3 may be omitted. In this case, the intermediate chamber 14 is also unnecessary.

(Second Embodiment)
FIG. 8 shows a second embodiment of the present invention. Here, the same components as those in the first embodiment are designated by the same reference numerals (which will be specifically described below), and detailed description thereof will be omitted.

In the first embodiment, the LNG evaporator E2 is arranged in the shell 11 of the intermediate medium evaporator E1, whereas in the second embodiment, the LNG evaporator E2 is the shell 67 of the intermediate medium evaporator E1. A circulation pipe 66 is provided on the outside of the above surface to connect the LNG evaporator E2 and the intermediate medium evaporator E1 to each other. The circulation pipe 66 extends into the shell 67 from the first pipe 66a connecting the upper surface of the shell 67 of the intermediate medium evaporator E1 and the upper surface of the header 68 (described later) of the LNG evaporator E2 and the lower surface of the liquid reservoir 45. It has a second pipe 66b.

The intermediate medium evaporator E1 includes a large number of heat transfer tubes 20 provided in the shell 67. The shell 67 is filled with a liquid intermediate medium M up to a position where all the heat transfer tubes 20 are immersed.

The LNG evaporator E2 has a configuration in which a liquid reservoir 45 is provided on the lower surface and a header 68 is provided on the upper surface. The lower surface of the header 68 is formed in an open hollow shape. An introduction port for introducing the intermediate medium M flowing through the first pipe 66a is formed on the upper surface of the header 68. The gaseous intermediate medium M that has flowed into the header 68 through the introduction port flows into each of the first flow paths 41a in the laminated body 38. In the present embodiment, the LNG evaporator E2 is configured by a microchannel heat exchanger, but is not limited to this, and may be configured by, for example, a plate fin heat exchanger.

The second pipe 66b functions as a liquid sealing pipe. The second pipe 66b extends to the inside of the shell 67, and the lower end of the second pipe 66b is located below the liquid level of the liquid intermediate medium M in the intermediate medium evaporator E1. That is, the liquid intermediate medium M is filled from the liquid level in the intermediate medium evaporator E1 to the second pipe 66b and the liquid reservoir 45.

In the present embodiment, also in the warmer E3, the laminated heat exchanger E3a is provided outside the housing 70 of the heat transfer tube type heat exchanger E3b. That is, the warmer E3 is composed of an intermediate medium type heat exchanger, and is a heat transfer tube type heat exchanger E3b that exchanges heat between the heat source medium (for example, seawater) and the intermediate medium M2, and the intermediate media M2 and NG. It is provided with a laminated heat exchanger E3a for heat exchange between the two, and a connecting pipe 69 for connecting the heat transfer tube type heat exchanger E3b and the laminated heat exchanger E3a to each other. The connection pipe 69 is from the first connection pipe 69a connecting the upper surface of the housing 70 of the heat transfer tube type heat exchanger E3b and the upper surface of the header 72 (described later) of the laminated heat exchanger E3a, and from the lower surface of the liquid reservoir 59. It has a second connection pipe 69b extending to the liquid level in the housing 70 of the heat transfer tube type heat exchanger E3b.

The heat transfer tube type heat exchanger E3b has a large number of heat transfer tubes 54 arranged in the housing 70, and a heat source medium such as seawater flows in the heat transfer tube 54. The housing 70 is filled with the liquid intermediate medium M2 to a position where all the heat transfer tubes 54 are immersed.

The laminated heat exchanger E3a has a configuration in which a liquid reservoir 59 is provided on the lower surface and a header 72 is provided on the upper surface. The lower surface of the header 72 is formed in an open hollow shape. An introduction port for introducing the intermediate medium M flowing through the first connection pipe 69a is formed on the upper surface of the header 72. The gaseous intermediate medium M that has flowed into the header 72 through the introduction port flows into each first flow path 56a in the laminated body.

In the present embodiment, the laminated heat exchanger E3a is composed of a microchannel heat exchanger, but the present invention is not limited to this, and for example, a plate fin heat exchanger may be used.

In the second embodiment, in the LNG evaporator E2, when the liquid intermediate medium M exchanges heat with LNG, it condenses. As a result, the pressure in the first flow path 41a of the LNG evaporator E2 decreases, so that the gaseous intermediate medium M vaporized by the intermediate medium evaporator E1 is sucked into the LNG evaporator E2 through the first pipe 66a. .. The liquid intermediate medium M condensed in the LNG evaporator E2 is stored in the liquid reservoir 45. Since the liquid intermediate medium M is also stored in the second pipe 66b, the lower side of the first flow path 41a is blocked by the liquid intermediate medium M. Therefore, the force that the liquid intermediate medium M in the liquid reservoir 45 and the second pipe 66b tries to lower acts as the suction force of the gaseous intermediate medium M into the first flow path 41a. As a result, the intermediate medium M flows from the first pipe 66a into the LNG evaporator E2.

The NG gasified in the LNG evaporator E2 is introduced into the laminated heat exchanger E3a of the warmer E3 through the outlet pipe 32. The NG is heated by the intermediate medium M2 in the laminated heat exchanger E3a and supplied to the user side. A natural circulation of the intermediate medium M2 occurs between the laminated heat exchanger E3a and the heat transfer tube type heat exchanger E3b as well as the circulation of the intermediate medium M between the intermediate medium evaporator E1 and the LNG evaporator E2.

According to the second embodiment, the shell 67 of the intermediate medium evaporator E1 can be miniaturized. Further, when the laminated heat exchanger (LNG evaporator E2) is abnormal, the intermediate medium evaporator E1 does not get in the way, which facilitates inspection and the like.

In the second embodiment, the second pipe 66b extends to the inside of the shell 67, and the lower end of the second pipe 66b is located below the liquid level of the liquid intermediate medium M in the intermediate medium evaporator E1. However, the lower end of the second pipe 66b may be located above the liquid level of the intermediate medium M. In this case, the second pipe 66b does not function as a liquid sealing pipe. The same applies to the heat transfer tube type heat exchanger E3b of the warmer E3. That is, the second connection pipe 69b extends to the inside of the housing 70, and the lower end of the second connection pipe 69b is below the liquid level of the liquid intermediate medium M2 in the housing 70 of the heat transfer tube heat exchanger E3b. However, the lower end of the second connecting pipe 69b may be located above the liquid level of the liquid intermediate medium M2.

In the second embodiment, the warmer E3 may be configured as a multi-tube heat exchanger E3b, similar to the configuration of FIG. 7. That is, as shown in FIG. 9, the laminated heat exchanger E3a constituting the warmer E3 may be omitted, and seawater as a heat source medium and NG may directly exchange heat in the heat transfer tube.

The other configurations, actions, and effects are the same as those of the first embodiment and its modifications, although the description thereof will be omitted.

10 Intermediate medium type vaporizer 11 Shell 20 Heat transfer tube 38 Laminated body 41 1st flow path layer 41a 1st flow path 42 2nd flow path layer 42a 2nd flow path 43 End plate 45 Liquid reservoir 46 Liquid seal tube E1 Intermediate medium evaporation Vessel E2 LNG evaporator

Claims (4)

An intermediate medium evaporation section having a shell in which an intermediate medium is housed and evaporating at least a part of the intermediate medium by heat exchange between the heat source medium and the liquid intermediate medium in the shell.
A liquefied gas vaporization unit that vaporizes the low-temperature liquefied gas and causes the gas to flow out by condensing the intermediate medium evaporated in the intermediate medium evaporation unit is provided.
The liquefied gas vaporization unit includes a first flow path layer having a plurality of first flow paths, which is a flow path of an intermediate medium, and a second flow path layer having a plurality of second flow paths, which is a flow path of a low-temperature liquefied gas. Consists of a laminated heat exchanger with a laminated body
The stacked heat exchanger, the intermediate medium evaporating portion of the disposed within the shell Rutotomoni are open to the upper portion of the plurality of first flow path in each of said shell,
The stacked heat exchanger, the intermediate medium flowing from each of the through openings of the upper portion intermediate medium evaporator portion of the inner shell to the plurality of first flow path of the plurality of first flow path the second installed in one flow path so that to the outflow flows down by gravity from said first flow path, in a posture in which the first flow path extending in a direction inclined with respect to the attitude or the vertical direction extending downward from the upper portion Intermediate medium type vaporizer that has been used. The intermediate medium type vaporizer according to claim 1, wherein the liquefied gas vaporization unit is provided with a liquid reservoir in which a liquid intermediate medium is stored on the downstream side of the first flow path. A liquid sealing tube for connecting the liquid reservoir and the liquid level of the liquid intermediate medium accumulated in the intermediate medium evaporation portion is further provided.
The intermediate medium type vaporizer according to claim 2, wherein the intermediate medium evaporation unit is located below the liquefied gas vaporization unit. The intermediate medium type vaporizer according to any one of claims 1 to 3, wherein the laminated heat exchanger is a microchannel heat exchanger.

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