WO2024080285A1 - Liquefied gas vaporizer - Google Patents

Abstract

The present invention makes effective use of the cold energy of a liquefied gas and suppresses effects on the environment.　A liquefied gas vaporizer 200 has a heat exchange part 210 that performs a heat exchange between liquefied natural gas (LNG) and brine B, a storage tank 280 that stores the brine B, and a circulation part 280 that circulates the brine B between the storage tank 280 and the heat exchange part 210. The heat exchange between the LNG and the brine B at the heat exchange part 210 evaporates the LNG to generate natural gas (NG) and cools the brine B to generate an ice slurry.

Description

Liquefied Gas Vaporizer

The present invention relates to a liquefied gas vaporizer.

Patent Document 1 discloses an LNG vaporizer that vaporizes LNG (liquefied natural gas). This LNG vaporizer is an open rack type LNG vaporizer (ORV) and has multiple heat exchange panels, a lower manifold that connects the heat exchange panels in parallel at their lower ends, and an upper manifold that connects the heat exchange panels in parallel at their upper ends. Each heat exchange panel also has multiple heat transfer tubes that extend vertically and are arranged side by side in the horizontal direction, a lower header tube that is connected to the lower manifold and connects the heat transfer tubes in parallel at their lower ends, and an upper header tube that is connected to the upper manifold and connects the heat transfer tubes in parallel at their upper ends. The LNG vaporizer also has a trough that stores seawater to be supplied to the outer surface of each heat transfer tube, and seawater supply means that supplies seawater to the trough.

In such an LNG vaporizer, LNG is introduced from the lower manifold through the lower header pipe into each heat transfer tube from the lower end. Meanwhile, seawater stored in the trough by the seawater supply means overflows from the trough and hangs down while wetting the outer surface of the heat transfer tube. The LNG introduced into the heat transfer tube is heated and vaporized by the seawater flowing outside the heat transfer tube, becoming NG (natural gas), which rises inside the heat transfer tube. This NG is led from the top of the heat transfer tube through the upper header pipe to the upper manifold. In this way, the LNG vaporizer of Patent Document 1 is a type of heat exchanger that generates NG by heating and vaporizing LNG through heat exchange with seawater.

JP 2013-148253 A

In LNG vaporizers like the one above, seawater is supplied from the ocean to the trough using a seawater supply means, and the cooled seawater overflows from the trough and hangs down the outer surface of the heat transfer tube, before being returned to the ocean. This means that the cold energy of the LNG is dumped into the ocean, and the cold energy of the LNG cannot be used effectively. Also, if the temperature difference ΔT between the seawater before and after it is used to heat the LNG is large, it can lead to a drop in the seawater temperature, which could have an impact on the environment of the ocean and its surrounding areas. To avoid this, the temperature difference ΔT is kept within about 2.0°C, but this requires a large amount of seawater to be continuously supplied to the heat transfer tube, which can easily increase operating costs.

The object of the present invention is to provide a liquefied gas vaporizer that can effectively utilize the cold energy of liquefied gases such as LNG and LPG while minimizing the impact on the environment.

This objective is achieved by the present invention described below.

(1) a heat exchange unit that exchanges heat between the liquefied gas and a medium to be cooled;
a storage tank for storing the medium to be cooled;
a circulation unit that circulates the cooled medium between the storage tank and the heat exchange unit,
A liquefied gas vaporizer characterized in that the liquefied gas is vaporized to generate gas and the cooled medium is cooled by heat exchange between the liquefied gas and the cooled medium in the heat exchange section.

(2) The medium to be cooled is salt water,
The liquefied gas vaporizer described in (1) above, wherein the salt water is cooled by heat exchange between the liquefied gas and the cooled medium in the heat exchange section to generate ice slurry, and the ice slurry is stored in the storage tank.

(3) The heat exchange unit has a heat transfer tube into which the liquefied gas is introduced,
The liquefied gas vaporizer according to (1) above, wherein heat exchange between the liquefied gas and the cooled medium is performed by the cooled medium hanging down the outer surface of the heat transfer tube.

(4) The circulation unit includes a trough disposed above the heat exchange unit and configured to store the cooled medium, and a first pipe connecting the storage tank and the trough and supplying the cooled medium in the storage tank to the trough,
The liquefied gas vaporizer according to the above (3), wherein the cooled medium overflowing from the trough is supplied to a heat transfer tube.

(5) The liquefied gas vaporizer described in (4) above, in which the circulation section includes a recovery tank that recovers the cooled medium from the heat transfer tube hanging down, and a second pipe that connects the recovery tank to the storage tank and introduces the cooled medium in the recovery tank into the storage tank.

(6) The liquefied gas vaporizer described in (1) above, wherein the heat exchange unit has an outer tube into which the cooled medium is introduced and a heat transfer tube disposed within the outer tube into which the liquefied gas is introduced.

(7) A liquefied gas vaporizer as described in (1) above, in which the heat exchange section exchanges heat between the liquefied gas and the cooled medium via an intermediate medium.

(8) A liquefied gas vaporizer as described in (1) above, which is installed at a receiving base for the liquefied gas.

The liquefied gas vaporizer of the present invention vaporizes the liquefied gas to generate gas through heat exchange between the liquefied gas and the cooled medium, while also cooling the cooled medium. In other words, the cold energy of the liquefied gas is used to cool the cooled medium. This allows for effective use of the cold energy of the liquefied gas. In addition, because the liquefied gas is vaporized using the cooled medium, rather than seawater as in the past, problems such as a drop in seawater temperature do not occur as in the past, and the environmental burden can also be reduced.

FIG. 1 is a diagram showing an LNG receiving terminal. FIG. 2 is a diagram showing the liquefied gas vaporizer according to the first embodiment. FIG. 3 is a diagram showing a heat exchange panel of the liquefied gas vaporizer of FIG. FIG. 4 shows the use of ice slurry in an air conditioning system. FIG. 5 is a diagram showing a state in which the ice slurry is used for quick freezing of an object to be kept cold. FIG. 6 is a diagram showing a liquefied gas vaporizer according to the second embodiment. FIG. 7 is a diagram showing a liquefied gas vaporizer according to the third embodiment. FIG. 8 is a diagram showing a liquefied gas vaporizer according to the fourth embodiment. FIG. 9 is a diagram showing a liquefied gas vaporizer according to the fifth embodiment.

The liquefied gas vaporizer of the present invention will be described in detail below based on each embodiment shown in the attached drawings. The liquefied gas vaporized by the liquefied gas vaporizer of the present invention is not particularly limited, but typically includes LNG (liquefied natural gas) and LPG (liquefied petroleum gas). However, the liquefied gas may be anything other than LNG or LPG, such as hydrogen gas (liquefied hydrogen) or liquefied ammonia (liquid ammonia). For ease of explanation, each of the following embodiments will be described using an example in which LNG is used as the liquefied gas, but the liquefied gas vaporizer of each embodiment can vaporize liquefied gases other than LNG, such as LPG, in the same way as LNG.

First Embodiment
First, we will briefly explain how NG (natural gas) is supplied in Japan. In Japan, most of the NG is imported. In addition, there are no pipelines between Japan and the countries where NG originates, so NG is imported by sea transport. In order to increase the efficiency of transportation, as shown in FIG. 1, the NG is converted into LNG (liquefied natural gas) at about -162°C by a liquefaction plant installed in a natural gas field 190, and then transported to about 40 receiving terminals 100 in Japan using LNG tankers 180.

The receiving terminal 100 is equipped with LNG tanks 120 for temporarily storing the transported LNG, a liquefied gas vaporizer 130 for vaporizing the LNG stored in the LNG tanks 120 to produce the required amount of natural gas NG, and an odorizer 140 for adding an odor to the NG produced by the liquefied gas vaporizer 130. The NG odorized by the odorizer 140 is sent to and stored in gas holders 150 installed in various locations in urban areas, etc., and is then sent to each contracted party through gas pipes.

In the case of an LPG receiving terminal, it has an LPG tank for temporarily storing the transported LPG, a liquefied gas vaporizer for vaporizing the LPG stored in the LPG tank to produce the required amount of gas, an odorizer for adding an odor to the gas produced by the liquefied gas vaporizer, and a gas holder for storing the gas odorized by the odorizer. The gas stored in the gas holder is then transported to the required location by tanker truck or the like.

As mentioned above, conventionally, LNG is vaporized (evaporated) using seawater in the liquefied gas vaporizer 130, but with this method, the cold energy of the LNG is dumped into the ocean together with the seawater, making it impossible to effectively utilize the cold energy of the LNG and placing a heavy burden on the environment. Therefore, in the liquefied gas vaporizer 130 of this embodiment, brine B (salt water) is used as a cooled medium instead of seawater, and LNG is vaporized (evaporated) by heat exchange between the LNG and brine B to produce NG, and the brine B is cooled to produce ice slurry I.

With the liquefied gas vaporizer 130 configured in this way, the cold energy of the LNG can be used to cool the brine B. This allows for effective use of the cold energy of the LNG. Furthermore, because the LNG is vaporized using the brine B instead of seawater, problems such as a drop in seawater temperature, which occurred in the past, do not occur, and the burden on the environment can also be reduced.

Note that, although it depends on the salinity, brine B is around -22°C to -1°C, whereas LNG is around -162°C. Therefore, a lot of heat is exchanged between the two, and both ice slurry I and LNG are efficiently produced. In particular, by using brine B as the cooled medium, ice slurry I that can be used for a variety of purposes can be produced, making the liquefied gas vaporizer 130 more convenient.

The uses of the ice slurry I produced by the liquefied gas vaporizer 130 are not particularly limited, and examples include quick freezing (instantaneous freezing) of fresh foods (mainly marine products such as fish, shellfish, and crustaceans), non-frozen storage, and air conditioning systems such as cooling, refrigeration, and freezing.

Ice slurry I is sherbet-like ice in which fine ice particles are mixed in salt water, and is also called slurry ice, ice slurry, or slurry ice. The salt concentration of the brine B is not particularly limited and is set appropriately depending on the use of the ice slurry I. As will be described later, for example, if it is to be used for the quick freezing of fresh foods, the salt concentration is preferably about 25% (saturation concentration). This allows the temperature of the ice slurry I to be lowered to about -22°, allowing the fresh foods to be frozen more quickly. Furthermore, if it is to be used for the frozen preservation of fresh foods, the salt concentration is preferably about 1%. This allows the temperature of the ice slurry I to be lowered to about -1°, allowing the fresh foods to be preserved in an unfrozen state at a lower temperature.

Next, the liquefied gas vaporizer 130 will be described. As described above, the liquefied gas vaporizer 130 is installed at the LNG receiving terminal 100 and is connected between the LNG tank 120 and the odorizer 140. This makes it easy to supply LNG to the liquefied gas vaporizer 130. However, the location where the liquefied gas vaporizer 130 is installed is not particularly limited.

As shown in FIG. 2, the liquefied gas vaporizer 130 of this embodiment is an open rack type liquefied gas vaporizer 200. The liquefied gas vaporizer 200 has a heat exchange section 210 that performs heat exchange between LNG and brine B, a storage tank 280 that stores brine B, and a circulation section 290 that circulates brine B between the storage tank 280 and the heat exchange section 210. Then, by the heat exchange between LNG and brine B in the heat exchange section 210, LNG is vaporized (evaporated) to become NG, and the brine B is cooled to become ice slurry I. The NG generated by heat exchange with the brine B is sent to the odorizer 140. On the other hand, the ice slurry I generated by heat exchange with LNG is stored in the storage tank 280, and only the required amount is taken out from the storage tank 280 when necessary and used.

The heat exchange section 210 has a plurality of heat exchange panels 211 arranged in a horizontal line. As shown in FIG. 3, each heat exchange panel 211 has a plurality of heat transfer tubes 212 extending in a vertical direction and arranged in a horizontal line, a lower header tube 213 connecting the heat transfer tubes 212 at their lower ends, and an upper header tube 214 connecting the heat transfer tubes 212 at their upper ends.

The lower header pipes 213 of each heat exchange panel 211 are connected to a lower manifold 220, which is connected to the LNG tank 120. The upper header pipes 214 of each heat exchange panel 211 are connected to an upper manifold 230, which is connected to the odorizer 140.

Then, the LNG discharged from the LNG tank 120 is introduced into each heat transfer tube 212 of each heat exchange panel 211 from the lower end side via the lower manifold 220. The LNG introduced into the heat transfer tube 212 is vaporized (evaporated) by heat exchange with the brine B to become NG. The NG thus generated rises inside the heat transfer tube 212 and is introduced into the odorizer 140 from the upper end side of the heat transfer tube 212 via the upper manifold 230.

As shown in FIG. 2, the circulation unit 290 has a trough 291 (weir), a first pipe 292 connecting the trough 291 and the storage tank 280, a recovery tank 294, and a second pipe 295 connecting the recovery tank 294 and the storage tank 280. The circulation unit 290 also has a pump (not shown) for circulating the brine B.

The troughs 291 are disposed above each heat exchange panel 211. Brine B is supplied to each of the troughs 291 from the storage tank 280 through the first pipe 292. This allows brine B to accumulate in each trough 291. The brine B accumulated in the trough 291 overflows from the trough 291 and hangs down while wetting the outer surface of each heat transfer tube 212 of the heat exchange panel 211. At this time, heat exchange occurs between the LNG in each heat transfer tube 212 and the brine B, and the LNG vaporizes and becomes NG. According to such a heat exchange section 210, heat exchange between the LNG and the brine B can be performed efficiently with a simple configuration. In particular, by configuring the brine B overflowing from the trough 291 to be supplied to the heat exchange section 210, the supply of brine B to the heat exchange section 210 is stabilized.

The recovery tank 294 is disposed below each heat exchange panel 211 and recovers the brine B that hangs down from each heat exchange panel 211. The brine B recovered in the recovery tank 294 is introduced into the storage tank 280 through the second pipe 295. This allows the brine B supplied to the heat exchange section 210 to be easily recovered. The circulation section 290 circulates the brine B between the storage tank 280 and the heat exchange section 210 with the above configuration. By continuing to circulate the brine B between the storage tank 280 and the heat exchange section 210, the brine B is gradually cooled by heat exchange with the LNG in the heat exchange section 210, and gradually some of it freezes to become ice, generating a sherbet-like ice slurry I in which fine ice is mixed in salt water. The ice slurry I generated in this manner is then stored in the storage tank 280.

Here, the liquefied gas vaporizer 200 of this embodiment has multiple storage tanks 280. In addition, the first pipe 292 is provided with a valve B1 for each storage tank 280. Therefore, by controlling the opening and closing of each valve B1, it is possible to select which storage tank 280 the brine B in to be supplied to the heat exchange section 210, that is, which storage tank 280 the brine B in to be cooled is to be selected. Similarly, the second pipe 295 is provided with a valve B2 for each storage tank 280. Then, by controlling the opening and closing of each valve B2, it is possible to select which storage tank 280 the brine B cooled by heat exchange is to be introduced into.

Furthermore, in this embodiment, the salinity of the brine B differs for each storage tank 280. In other words, a different type of brine B is stored in each storage tank 280. For example, storage tank 280A stores brine B with a salinity of 1%, storage tank 280B stores brine B with a salinity of 10%, and storage tank 280C stores brine B with a salinity of 25% (saturation concentration).

Therefore, for example, if it is desired to generate ice slurry I with a salinity of 1%, the valves B1 and B2 of the storage tank 280A are opened, and the valves B1 and B2 of the storage tanks 280B and 280C are closed, and the brine B in the storage tank 280A is circulated to the heat exchange section 210.

Similarly, to generate ice slurry I with a salinity of 10%, valves B1 and B2 of storage tank 280B are opened, valves B1 and B2 of storage tanks 280A and 280C are closed, and the brine B in storage tank 280B is circulated to heat exchange section 210. To generate ice slurry I with a salinity of 25%, valves B1 and B2 of storage tank 280C are opened, valves B1 and B2 of storage tanks 280A and 280B are closed, and the brine B in storage tank 280C is circulated to heat exchange section 210.

In this way, by varying the salt concentration of the brine B for each storage tank 280, ice slurries I of various concentrations can be generated and stored. However, this is not limited to this, and brine B with the same salt concentration may be stored in all storage tanks 280. Also, there may be only one storage tank 280.

Each storage tank 280 is provided with a discharge port 281 for discharging the ice slurry I stored therein, and a supply port 282 for supplying brine B therein. When ice slurry I is used, the required amount of ice slurry I can be taken out through the discharge port 281. Furthermore, when the amount of brine B inside falls below a predetermined amount due to use of ice slurry I, brine B can be replenished through the supply port 282.

In addition, although not shown, each storage tank 280 is equipped with a stirring blade for stirring the stored brine B. This makes it possible to suppress the aggregation of ice slurry I within the storage tank 280.

The liquefied gas vaporizer 200 also has a heating mechanism 270 that heats the ice slurry I to melt at least a portion of the ice. For example, if the amount of ice slurry I used is small relative to the amount of NG produced (the amount of LNG supplied), there is little opportunity to raise the temperature of the brine B by refilling it with new brine B, so the brine B in the storage tank 280 is excessively cooled, the ice content of the ice slurry I becomes excessively high, the fluidity of the brine B deteriorates, and the production of NG may be hindered. Therefore, the fluidity of the brine B is maintained by heating the ice slurry I in the storage tank 280 with the heating mechanism 270 to melt at least a portion of the ice. Therefore, even if the amount of ice slurry I used is small relative to the amount of NG produced, NG can be produced continuously and continuously.

The heating mechanism 270 of this embodiment has a heater 271 arranged in each storage tank 280. With this configuration, the ice slurry I in the storage tank 280 can be heated simply and efficiently by driving the heater 271. It is possible to arbitrarily select which storage tank 280 contains the ice slurry I to be heated.

However, the configuration of the heating mechanism 270 is not particularly limited. For example, the heater 271 may be disposed in the first pipe 292 to heat the brine B passing through the first pipe 292. The heater 271 may also be disposed in the recovery tank 294 to heat the brine B recovered in the recovery tank 294. The mechanism may also heat the ice slurry I without using a heater, such as by heating the ice slurry I through heat exchange with a heat generating part (e.g., a motor, a pump, etc.) in the liquefied gas vaporizer 200 or with the outside air.

The above describes the liquefied gas vaporizer 200. Next, the uses of the ice slurry I generated by the liquefied gas vaporizer 200 will be described. One use is an air conditioning system 700. For example, as shown in FIG. 4, building X is equipped with an ice slurry storage tank 710 and an air conditioner 720 installed indoors as the air conditioning system 700, and a pipe 730 connecting the suction port 721 and the blowing port 722 of the air conditioner 720 passes through the ice slurry storage tank 710.

The ice slurry storage tank 710 stores a sufficient amount of ice slurry I produced by the liquefied gas vaporizer 200, and the indoor air sucked in from the suction port 721 is cooled by the cold energy of the ice slurry I as it passes through the ice slurry storage tank 710, and is blown out from the blowout port 722 into the room. This allows the room to be cooled. The ice slurry I keeps the temperature of the ice slurry I near the melting point of the brine B until the ice components (solid components) melt due to the action of latent heat. The heat of fusion required to turn a solid into a liquid is much higher than the specific heat of the liquid, so the ice slurry I functions as a highly efficient heat storage material and allows the indoor air to be cooled for a longer period of time.

However, there are no particular limitations on the air conditioning system 700, so long as it uses ice slurry I. For example, it may be a conventionally known ice thermal storage air conditioning system. Furthermore, the air conditioning system may be used to cool the inside of a refrigerator or freezer, rather than just cooling a room.

Another use of ice slurry I is the rapid freezing of marine products (item F) such as fish, shellfish, and crustaceans. In this case, as shown in FIG. 5, the item F is placed in an insulated polystyrene foam box filled with ice slurry I. Because ice slurry I has a large specific surface area, it can quickly freeze the item F. In addition, the above-mentioned latent heat effect allows the item F to be frozen for a long time. Therefore, the item F can be kept cold for a long time while maintaining its freshness. In addition, ice slurry I is soft and does not damage the item F even when it comes into contact (collisions) with it.

Here, the higher the salt concentration of the brine B, which is the raw material for the ice slurry I used in the air conditioning system 700 and the rapid freezing process of the refrigerated object F, the better, and it is particularly preferable that it is saturated. In other words, it is preferable that the brine B is saturated salt water. The higher the salt concentration, the lower the melting point of the brine B, and the melting point of saturated brine B is about -22°C. Therefore, the ice slurry I becomes colder, which enhances the air conditioning effect described above and enables the refrigerated object F to be frozen more quickly.

Another use of ice slurry I is the non-frozen low-temperature preservation of marine products (item F) such as fish, shellfish, and crustaceans. In this case, as with the quick freezing process, the item F is placed in a polystyrene foam insulation box and filled with ice slurry I. Because ice slurry I has a large specific surface area, it can quickly cool the item F. In addition, the above-mentioned latent heat effect allows the item F to be kept at low temperatures for a long period of time. Therefore, the item F can be kept cold for a long period of time while maintaining its freshness. In addition, ice slurry I is soft and does not damage the item F even when it comes into contact (collisions) with it.

The salt concentration of the brine B, which is the raw material for the ice slurry I used to preserve the refrigerated item F without freezing, is preferably around 1%. This makes the melting point of the brine B around -1°C, and the temperature of the ice slurry I is maintained at around -1°C. Since seafood such as fish freezes at around -2°C, by maintaining the temperature of the ice slurry I at around -1°C, the seafood can be stored for a long time at a lower temperature while preventing it from freezing. This makes the above-mentioned effects even more pronounced.

Second Embodiment
Next, a liquefied gas vaporizer according to a second embodiment will be described. As shown in Fig. 6, in the liquefied gas vaporizer according to this embodiment, a storage tank 280 is connected to a freezing tank 250, and ice slurry I is circulated between the storage tank 280 and the freezing tank 250. The object F to be cooled can be immersed in the ice slurry I stored in the freezing tank 250 to perform a quick freezing process. With this configuration, fresh ice slurry I is continuously supplied to the freezing tank 250, so that the quick freezing process of the object F to be cooled can be easily and reliably performed.

The second embodiment described above can also achieve the same effects as the first embodiment described above. Note that in this embodiment, for convenience of explanation, there is only one storage tank 280, but the number of storage tanks 280 is not particularly limited. For example, if there are multiple storage tanks 280, all of the storage tanks 280 may be connected to the same freezing tank 250, or each storage tank 280 may be connected to a different freezing tank 250.

Third Embodiment
Next, a liquefied gas vaporizer according to a third embodiment will be described. In the first embodiment described above, one liquefied gas vaporizer 200 is used to vaporize LNG to generate NG, but in this embodiment, multiple liquefied gas vaporizers 200 are used to vaporize LNG to generate NG. Since LNG has an ultra-low temperature of about -162°C, it may not be possible to sufficiently vaporize LNG depending on the capacity of the liquefied gas vaporizer 200, and some of the LNG may pass through the liquefied gas vaporizer 200 in the LNG state.

In this embodiment, therefore, as shown in FIG. 7, multiple liquefied gas vaporizers 200 are connected in series. With this configuration, heat exchange with the brine B occurs each time the LNG passes through each liquefied gas vaporizer 200, so that the LNG can be more reliably vaporized to produce NG. In other words, NG can be more reliably sent out from the last liquefied gas vaporizer 200. Note that, although three liquefied gas vaporizers 200 are connected in the illustrated configuration, the number of liquefied gas vaporizers 200 is not particularly limited.

Here, the brine B may be different for each liquefied gas vaporizer 200, or may be the same. If they are different, for example, the first liquefied gas vaporizer 200 may use brine B with a saturated concentration, the next liquefied gas vaporizer 200 may use brine B with a salinity of 10%, and the last liquefied gas vaporizer 200 may use brine B with a salinity of 1%. This allows ice slurries I with different concentrations to be generated simultaneously. Also, the type of cooled medium may be different for each liquefied gas vaporizer 200. For example, the first liquefied gas vaporizer 200 may use brine B, the next liquefied gas vaporizer 200 may use sodium chloride, and the last liquefied gas vaporizer 200 may use alcohol.

The third embodiment described above can also achieve the same effects as the first embodiment described above.

Fourth Embodiment
Next, a liquefied gas vaporizer according to a fourth embodiment will be described. The liquefied gas vaporizer of this embodiment is similar to the liquefied gas vaporizer of the first embodiment described above, except that the configurations of the heat exchange section and the circulation section are different. Therefore, in the following description, the liquefied gas vaporizer of this embodiment will be described with a focus on the differences from the first embodiment described above, and the description of the similar points will be omitted. In addition, in the drawings of this embodiment, the same reference numerals are used for the same configurations as the above-mentioned embodiment.

As shown in FIG. 8, the heat exchange section 210 of the liquefied gas vaporizer 200 of this embodiment has an outer pipe 219 into which brine B is introduced. Each heat transfer tube 212 of each heat exchange panel 211 is arranged inside this outer pipe 219. Brine B is supplied to the upper end side of the outer pipe 219, and brine B is discharged from the lower end side. Each heat transfer tube 212 is arranged so as to penetrate the outer pipe 219 from top to bottom. With this heat exchange section 210, heat exchange between LNG and brine B can be performed with a simple configuration.

The circulation unit 290 also has a first pipe 292 that connects the outer pipe 219 and the storage tank 280, and a second pipe 295 that connects the outer pipe 219 and the storage tank 280. The circulation unit 290 also has a pump (not shown) for circulating the brine B.

The fourth embodiment described above can also achieve the same effects as the first embodiment described above.

Fifth Embodiment
Next, a liquefied gas vaporizer according to a fifth embodiment will be described. The liquefied gas vaporizer 130 of this embodiment is an intermediate medium type liquefied gas vaporizer 300. As shown in Fig. 9, the liquefied gas vaporizer 300 has a heat exchanger 310 that exchanges heat between LNG and brine B, a storage tank 380 that stores the brine B, and a circulation unit 390 that circulates the brine B between the storage tank 380 and the heat exchanger 310.

Then, due to heat exchange between the LNG and the brine B in the heat exchange section 310, the LNG vaporizes (evaporates) and becomes NG, and the brine B is cooled and becomes ice slurry I. The NG generated by heat exchange with the brine B is sent to the odorizer 140. Meanwhile, the ice slurry I generated by heat exchange with the LNG is stored in the storage tank 380, and only the required amount is taken out from the storage tank 280 when needed and used. Note that the storage tank 380 has the same configuration as the storage tank 280 in the first embodiment described above, so a description thereof will be omitted.

The heat exchange section 310 has an intermediate medium evaporator 320 with a shell 321, an LNG evaporator 330 arranged in the shell 321, and a heater 340 with a shell 341. An intermediate medium Q having a boiling point lower than the temperature of the brine B is stored in the shell 321 of the intermediate medium evaporator 320. The intermediate medium Q is not particularly limited, but may be, for example, propane. The LNG evaporator 330 has a third heat transfer tube 331 into which LNG is introduced. The LNG evaporator 330 is connected to the shell 341 of the heater 340 via a conduit 350.

The circulation section 390 has an inlet chamber 391 located at the end on the shell 341 side, an intermediate chamber 392 located between the shells 321 and 341, an outlet chamber 393 located at the end on the shell 321 side, a plurality of first heat transfer tubes 394 passing through the shell 341 and connecting the inlet chamber 391 and the intermediate chamber 392, a plurality of second heat transfer tubes 395 passing through the shell 321 and connecting the intermediate chamber 392 and the outlet chamber 393, a first pipe 396 connecting the inlet chamber 391 and the storage tank 380, and a second pipe 397 connecting the outlet chamber 393 and the storage tank 380. The circulation section 390 also has a pump (not shown) for circulating the brine B.

Furthermore, each second heat transfer tube 395 is disposed so as to pass through the liquid intermediate medium Q. In contrast, the third heat transfer tube 331 of the LNG evaporator 330 is disposed above the liquid intermediate medium Q so as to be in contact with the vaporized intermediate medium Q.

In such a liquefied gas vaporizer 300, the brine B passes through the inlet chamber 391, the first heat transfer tube 394, the intermediate chamber 392, and the second heat transfer tube 395 to reach the outlet chamber 393. At this time, heat exchange between the brine B and the intermediate medium Q is performed through the second heat transfer tube 395, and the intermediate medium Q is vaporized (evaporated) and the brine B is cooled. Meanwhile, the LNG is introduced into the third heat transfer tube 331 of the LNG evaporator 330. In the third heat transfer tube 331, heat exchange between the LNG and the vaporized intermediate medium Q is performed, the LNG is vaporized to generate NG, and the intermediate medium Q is condensed into droplets and falls into the shell 321. In this way, the intermediate medium Q repeatedly vaporizes and condenses, and heat exchange between the LNG and the brine B is performed through the intermediate medium Q. This allows efficient heat exchange between the LNG and the brine B.

The NG generated in the LNG evaporator 330 is introduced into the shell 341 of the heater 340 via the conduit 350, where it is heated by heat exchange with the brine B flowing inside the first heat transfer tube 394 and is sent out as room temperature gas.

The fifth embodiment described above can also achieve the same effects as the first embodiment described above.

The liquefied gas vaporizer of the present invention has been described above based on the illustrated embodiment, but the present invention is not limited to this. For example, the configuration of each part can be replaced with any configuration that performs the same function, and any configuration can be added.

In addition, in the above-described embodiment, the medium to be cooled was brine, but it is not limited to this and may be, for example, water, various types of drinking water, sodium chloride, calcium chloride, alcohol, etc. Also, as long as the medium to be cooled can be cooled, it does not have to be frozen. In other words, a liquefied gas vaporizer may be used like a chiller.

In the above embodiment, an example was described in which the liquefied gas vaporizer 130 was installed at the receiving base 100, but the location of the liquefied gas vaporizer 130 is not particularly limited, and may be, for example, a power plant that generates electricity using the gas produced by vaporizing liquefied gas as fuel, a liquefied gas satellite base (a base that receives LNG transported by tanker truck from the receiving base 100, gasifies it, and sends the gas to a contracted party to areas where there is no pipeline from the receiving base 100 and direct supply is not possible), etc.

As described above, the liquefied gas vaporizer of the present invention vaporizes the liquefied gas to generate gas through heat exchange between the liquefied gas and the cooled medium, and cools the cooled medium. In other words, the cold energy of the liquefied gas is used to cool the cooled medium. This allows the cold energy of the liquefied gas to be used effectively. Furthermore, because the liquefied gas is vaporized using the cooled medium, rather than using seawater as in the past, problems such as a drop in seawater temperature do not occur, and the environmental load can also be reduced. Therefore, the liquefied gas vaporizer of the present invention has industrial applicability.

100...receiving terminal, 120...LNG tank, 130...liquefied gas vaporizer, 140...odorizer, 150...gas holder, 180...LNG tanker, 190...natural gas field, 200...liquefied gas vaporizer, 210...heat exchange section, 211...heat exchange panel, 212...heat transfer tube, 213...lower header tube, 214...upper header tube, 219...outer tube, 220...lower manifold, 230...upper manifold, 250...freezing tank, 270...heating mechanism, 271...heater, 280...storage tank, 280A...storage tank, 280B...storage tank, 280C...storage tank, 281...discharge port, 282...supply port, 290...circulation section, 291...trough, 292...first piping, 293...first pump, 29 4...recovery tank, 295...second piping, 296...second pump, 300...liquefied gas vaporizer, 310...heat exchange section, 320...intermediate medium evaporator, 321...shell, 330...LNG evaporator, 331...third heat transfer tube, 340...heater, 341...shell, 350...conduit, 380...storage tank, 390...circulation section, 391...inlet chamber, 392...intermediate chamber, 393 ...Outlet chamber, 394...First heat transfer tube, 395...Second heat transfer tube, 396...First piping, 397...Second piping, 700...Air conditioning system, 710...Ice slurry storage tank, 720...Air conditioner, 721...Suction port, 722...Blow-out port, 730...Pipe line, B...Brine, B1...Valve, B2...Valve, F...Item to be cooled, I...Ice slurry, Q...Intermediate medium, X...Building

Claims (8)

a heat exchange unit for exchanging heat between the liquefied gas and the medium to be cooled;
a storage tank for storing the medium to be cooled;
a circulation unit that circulates the cooled medium between the storage tank and the heat exchange unit,
A liquefied gas vaporizer characterized in that the liquefied gas is vaporized to generate gas and the cooled medium is cooled by heat exchange between the liquefied gas and the cooled medium in the heat exchange section. The medium to be cooled is salt water,
2. The liquefied gas vaporizer according to claim 1, wherein the salt water is cooled by heat exchange between the liquefied gas and the cooled medium in the heat exchange section to generate ice slurry, and the ice slurry is stored in the storage tank. The heat exchange unit has a heat transfer tube into which the liquefied gas is introduced,
2. The liquefied gas vaporizer according to claim 1, wherein the medium to be cooled hangs down on the outer surface of the heat transfer tube, thereby performing heat exchange between the liquefied gas and the medium to be cooled. the circulation unit includes a trough disposed above the heat exchange unit and configured to store the cooled medium, and a first pipe connecting the storage tank and the trough and supplying the cooled medium in the storage tank to the trough,
4. A liquefied gas vaporizer according to claim 3, wherein the cooled medium overflowing from the trough is supplied to a heat transfer tube. The liquefied gas vaporizer according to claim 4, wherein the circulation section includes a recovery tank that recovers the cooled medium hanging down from the heat transfer tube, and a second pipe that connects the recovery tank to the storage tank and introduces the cooled medium in the recovery tank into the storage tank. The liquefied gas vaporizer according to claim 1, wherein the heat exchange section has an outer tube into which the cooled medium is introduced, and a heat transfer tube disposed within the outer tube into which the liquefied gas is introduced. The liquefied gas vaporizer according to claim 1, wherein the heat exchange section exchanges heat between the liquefied gas and the cooled medium via an intermediate medium. The liquefied gas vaporizer according to claim 1, which is installed at a receiving station for the liquefied gas.

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