JP2021008942A - Liquefied natural gas vaporizer and cold water supply method - Google Patents

Abstract

To provide a liquefied natural gas vaporizer capable of lowering a temperature of cold water flowing out from the vaporizer while suppressing icing.SOLUTION: A liquefied natural gas vaporizer includes: an intermediate medium evaporation section evaporating at least a part of a liquid intermediate medium by exchanging heat between the liquid intermediate medium and water; a liquefied natural gas vaporization section vaporizing at least a part of liquefied natural gas by exchanging heat between a gaseous intermediate medium generated by evaporation of the liquid intermediate medium in the intermediate medium evaporation section and the liquefied natural gas; and a water cooling part further cooling water by exchanging heat between natural gas generated by vaporization of the liquefied natural gas in the liquefied natural gas vaporization section and the water cooled by heat exchange with the liquid intermediate medium in the intermediate medium evaporation section via a heat transfer section.SELECTED DRAWING: Figure 1

Description

The present invention relates to a liquefied natural gas vaporizer and a cold water supply method.

Conventionally, as described in Patent Document 1, as a vaporizer for vaporizing liquefied natural gas (LNG), an intermediate medium type vaporizer (IFV) is known. The intermediate medium type vaporizer vaporizes LNG with a heat source such as seawater via an intermediate medium such as propane, and can suppress icing troubles as compared with a vaporizer that directly exchanges heat between the heat source and LNG. Is.

The intermediate medium type vaporizer described in Patent Document 1 has an intermediate medium evaporating unit that evaporates the intermediate medium by exchanging heat between the liquid phase intermediate medium and water, and an intermediate medium between the liquefied natural gas and the gas phase. It has a liquefied natural gas vaporization unit that vaporizes liquefied natural gas by exchanging heat. Further, the water cooled by the liquid phase intermediate medium in the intermediate medium evaporation section flows out from the intermediate medium evaporation section, and then cools the air for driving the gas turbine in the gas turbine combined cycle (GTCC). Introduced to the cooler.

JP-A-2018-119511

Here, in order to increase the power generation efficiency in the GTCC, it may be required to supply cold water at a lower temperature to the air cooler. However, in the intermediate medium type vaporizer described in Patent Document 1, if the temperature of the cold water flowing out from the intermediate medium evaporation part is lowered too much (for example, when the temperature is lowered to a temperature lower than 4 to 5 ° C.), the icing is formed on the inner surface of the heat transfer tube. There is a problem that ice is likely to occur. Therefore, conventionally, there is a problem that it is difficult to lower the temperature of the cold water flowing out of the vaporizer while suppressing icing.

The present invention has been made in view of the above problems, and an object of the present invention is a liquefied natural gas vaporizer capable of lowering the temperature of cold water flowing out of the vaporizer while suppressing icing, and the liquefied natural gas vaporization. It is to provide a cold water supply method using a vessel.

The liquefied natural gas vaporizer according to one aspect of the present invention has an intermediate medium evaporation section that evaporates at least a part of the liquid intermediate medium by exchanging heat between the liquid intermediate medium and water, and the intermediate medium evaporation. A liquefied natural gas vaporization unit that vaporizes at least a part of the liquefied natural gas by heat-exchanges between the gaseous intermediate medium generated by evaporation of the liquid intermediate medium and the liquefied natural gas. The heat transfer section transfers the natural gas generated by the vaporization of the liquefied natural gas in the liquefied natural gas vaporization section and the water cooled by heat exchange with the liquid intermediate medium in the intermediate medium evaporation section. It is provided with a water cooling unit that further cools the water by exchanging heat through the water.

The present inventors diligently studied measures for lowering the temperature of cold water flowing out of the liquefied natural gas vaporizer while suppressing icing, and obtained the following findings to come up with the present invention. ..

Generally, in an intermediate medium type liquefied natural gas vaporizer, a liquid intermediate medium is heated by water and evaporated, and the liquefied natural gas is heated by a gaseous intermediate medium to generate natural gas. Here, in the intermediate medium evaporation section where heat is exchanged between water and the intermediate medium, the intermediate medium that has recovered heat from water changes its state from the liquid phase to the gas phase, so that the boundary film heat transfer coefficient on the intermediate medium side becomes large. Therefore, in the intermediate medium evaporation section, the temperature of the heat transfer tube wall is closer to the temperature of the intermediate medium than the temperature of water, and tends to decrease. For this reason, it has been difficult for conventional liquefied natural gas vaporizers to lower the temperature of cold water flowing out of the vaporizer while suppressing icing.

Therefore, as a measure for solving the above problems, the present inventors and others utilize the cold heat of the natural gas generated in the liquefied natural gas vaporization section by using the water cooled by the liquid intermediate medium in the intermediate medium evaporation section. The idea was to provide a water cooling unit for further cooling. In this water cooling section, the state does not change when natural gas recovers heat from water, so the boundary film heat transfer coefficient on the natural gas side is smaller than the boundary film heat transfer coefficient on the intermediate medium side in the intermediate medium evaporation section. Become. Therefore, in the water cooling section, the temperature of the heat transfer tube wall is less likely to drop than in the intermediate medium evaporation section. Therefore, according to the liquefied natural gas vaporizer of the present invention, it is possible to suppress icing in the vaporizer even when the temperature of the cold water flowing out of the vaporizer is lowered to a temperature lower than, for example, 4 to 5 ° C. Become.

The liquefied natural gas vaporizer adds the natural gas by exchanging heat between the natural gas that has exchanged heat with the water in the water cooling unit and the water that has not flowed into the intermediate medium evaporation unit. It may further include a natural gas heating unit for heating.

According to this configuration, the temperature of the natural gas can be easily raised to the required temperature.

The cold water supply method according to another aspect of the present invention is a method of supplying the water flowing out from the water cooling portion of the liquefied natural gas vaporizer as cooling water for the gas turbine driving air in the gas turbine combined power generation device. is there.

According to this method, the gas turbine driving air can be cooled by the cold water cooled to a sufficiently low temperature by the water cooling unit. As a result, the water content of the air is reduced, so that the combustion efficiency is improved, and as a result, the power generation efficiency in the gas turbine combined power generation device can be increased.

As is clear from the above description, according to the present invention, a liquefied natural gas vaporizer capable of lowering the temperature of cold water flowing out of the vaporizer while suppressing icing and the liquefied natural gas vaporizer are used. A cold water supply method can be provided.

It is a figure which shows typically the structure of the liquefied natural gas vaporizer which concerns on Embodiment 1 of this invention. It is a figure which shows typically the structure of the gas turbine combined power generation apparatus. It is a figure which shows typically the structure of the liquefied natural gas vaporizer which concerns on Embodiment 2 of this invention.

Hereinafter, the liquefied natural gas vaporizer and the cold water supply method according to the embodiment of the present invention will be described in detail with reference to the drawings.

(Embodiment 1)
<Liquefied natural gas vaporizer>
First, the configuration of the liquefied natural gas vaporizer 1 according to the first embodiment of the present invention will be described with reference to FIG. The liquefied natural gas vaporizer 1 according to the present embodiment is an intermediate medium type vaporizer that vaporizes liquefied natural gas (LNG) with water W1 (for example, industrial water) via an intermediate medium, and is installed in the LNG base area. used. As shown in FIG. 1, the liquefied natural gas vaporizer 1 mainly includes an intermediate medium evaporation section E1, a liquefied natural gas vaporization section E2, a natural gas heating section E3, and a water cooling section E4. ..

The intermediate medium evaporation unit E1 evaporates at least a part of the liquid intermediate medium M1 by exchanging heat between the liquid intermediate medium M1 and the water W1. The intermediate medium M1 is a heat medium having a boiling point and a condensation point between the temperature of water W1 and the temperature of LNG, for example, propane. The intermediate medium evaporation unit E1 in the present embodiment is composed of a shell-and-tube heat exchanger.

Specifically, as shown in FIG. 1, the intermediate medium evaporation section E1 is immersed in a shell 10 having a horizontally long shape and filled with a liquid intermediate medium M1 and a liquid intermediate medium M1. It has a plurality of heat transfer tubes 11 arranged at the lower part in the shell 10. A water inlet chamber 12 is provided on one side of the shell 10, and a water outlet chamber 13 is provided on the other side of the shell 10. Each of the plurality of heat transfer tubes 11 communicates with the water inlet chamber 12 and the water outlet chamber 13, and is arranged in a horizontal posture extending from the water inlet chamber 12 to the water outlet chamber 13.

In the intermediate medium evaporation section E1, the water W1 that has flowed into the heat transfer tube 11 from the water inlet chamber 12 exchanges heat with the liquid intermediate medium M1 in the process of flowing through the heat transfer tube 11 toward the water outlet chamber 13 (water W1). Dissipates heat from the liquid intermediate medium M1). As a result, the liquid intermediate medium M1 heat recovered from the water W1 evaporates to generate the gaseous intermediate medium M2, while the water W1 is cooled by recovering the cold heat from the liquid intermediate medium M1. The temperature of the liquid intermediate medium M1 is, for example, about −10 to −5 ° C., and the temperature of the cooled water W1 is, for example, about 4 to 5 ° C.

The liquefied natural gas vaporization unit E2 vaporizes at least a part of LNG by exchanging heat between the gaseous intermediate medium M2 generated by the evaporation of the liquid intermediate medium M1 in the intermediate medium evaporation unit E1 and the LNG. .. The liquefied natural gas vaporization unit E2 in the present embodiment is composed of a shell-and-tube heat exchanger like the intermediate medium evaporation unit E1.

As shown in FIG. 1, the liquefied natural gas vaporization unit E2 includes a shell 10, a U-shaped heat transfer tube 21 arranged above the shell 10 (above the liquid surface of the liquid intermediate medium M1), and the shell 10. have. An LNG inlet chamber 22 and an NG outlet chamber 23 are provided on the side portion of the shell 10 (upper side of the water outlet chamber 13), and both chambers are separated from each other by a partition plate 24. The heat transfer tube 21 has a pipe inlet 21A communicating with the LNG inlet chamber 22 and a pipe outlet 21B communicating with the NG outlet chamber 23, and extends horizontally from the pipe inlet 21A to one side and then bends. It has a shape extending from the bent portion toward the pipe outlet 21B on the other side in the horizontal direction.

In the liquefied natural gas vaporization section E2, LNG flows into the heat transfer tube 21 from the LNG inlet chamber 22, and the gaseous intermediate medium M2 generated in the intermediate medium evaporation section E1 rises to a position near the heat transfer tube 21. Then, LNG evaporates by recovering heat from the gaseous intermediate medium M2 to generate natural gas (NG; Natural Gas), while the gaseous intermediate medium M2 cooled by LNG condenses and shells 10. It collects on the bottom side of the inside. The NG flows out from the pipe outlet 21B of the heat transfer tube 21 into the NG outlet chamber 23.

The water cooling unit E4 heat transfers NG generated by vaporization of LNG in the liquefied natural gas vaporization unit E2 and water W1 cooled by heat exchange between the liquid intermediate medium M1 in the intermediate medium evaporation unit E1. The water W1 is further cooled by exchanging heat through the section. The water cooling unit E4 in the present embodiment is composed of a shell-and-tube heat exchanger like the intermediate medium evaporation unit E1 and the liquefied natural gas vaporization unit E2. As shown in FIG. 1, the water cooling unit E4 is connected to the liquefied natural gas vaporization unit E2 by the first connecting pipe 51, and is connected to the intermediate medium evaporation unit E1 by the second connecting pipe 52. Further, the water cooling unit E4 is on the NG flow path on the downstream side of the liquefied natural gas vaporizing unit E2 and on the upstream side of the natural gas heating unit E3 (the liquefied natural gas vaporizing unit E2 and the natural gas heating unit E3). Is located between).

More specifically, the water cooling unit E4 has a shell 41 having a long shape in the horizontal direction, a U-shaped heat transfer tube 42 arranged in the shell 41, and an NG inlet communicating with the pipe inlet 42A of the heat transfer tube 42. It has a chamber 43 and an NG outlet chamber 44 that communicates with the pipe outlet 42B of the heat transfer tube 42 and is partitioned from the NG inlet chamber 43 by a partition plate 45.

As shown in FIG. 1, the upstream end of the first connecting pipe 51 is connected to the NG outlet chamber 23 of the liquefied natural gas vaporization unit E2, and the downstream end is connected to the NG inlet chamber 43 of the water cooling unit E4. ing. Further, the upstream end of the second connecting pipe 52 is connected to the water outlet chamber 13 of the intermediate medium evaporation section E1, and the downstream end is connected to the water inlet 41A provided above the shell 41 of the water cooling section E4. ing.

The heat transfer tube 42 is for NG flowing out from the liquefied natural gas vaporization section E2, extends from the tube inlet 42A to one side in the horizontal direction and then bends, and then bends from the bent portion toward the pipe outlet 42B in the horizontal direction. It has a shape that extends to the side. The cooled water W1 flowing out from the intermediate medium evaporation section E1 flows into the space inside the shell 41 through the second connecting pipe 52, and the water W1 flows from the water outlet 41B provided at the lower part of the shell 41 to the shell 41. Outflow to the outside.

With the above configuration, the NG flowing out from the liquefied natural gas vaporization unit E2 (NG outlet chamber 23) flows into the NG inlet chamber 43 through the first connecting pipe 51, and then flows into the heat transfer pipe 42 from the pipe inlet 42A. .. Then, the NG circulates in the heat transfer tube 42 from the tube inlet 42A toward the tube outlet 42B, and then flows out into the NG outlet chamber 44.

On the other hand, the water W1 flowing out from the intermediate medium evaporation section E1 (water outlet chamber 13) flows into the shell 41 from the water inlet 41A through the second connecting pipe 52. Then, the water W1 exchanges heat with the NG flowing in the heat transfer tube 42 via the tube wall portion (heat transfer portion) of the heat transfer tube 42, and recovers the cold heat from the NG to be lower than 4 to 5 ° C. After being cooled to, it flows out of the shell 41 from the water outlet 41B. On the other hand, the NG is heated by recovering heat from the water W1 and then flows out from the pipe outlet 42B of the heat transfer tube 42 to the NG outlet chamber 44.

The natural gas heating unit E3 heats the NG by exchanging heat between the NG that has exchanged heat with the water W1 in the water cooling unit E4 and the water W1 that has not flowed into the intermediate medium evaporation unit E1. The natural gas heating unit E3 in the present embodiment is composed of a shell-and-tube heat exchanger like the intermediate medium evaporation unit E1, the liquefied natural gas vaporization unit E2, and the water cooling unit E4, and is composed of a third connecting pipe. It is connected to the water cooling unit E4 by 53.

As shown in FIG. 1, the natural gas heating unit E3 communicates with a shell 31 having a long shape in the horizontal direction, a U-shaped heat transfer tube 32 arranged in the shell 31, and a pipe inlet 32A of the heat transfer tube 32. It has an NG inlet chamber 33 that communicates with the NG inlet chamber 33, and an NG outlet chamber 34 that communicates with the pipe outlet 32B of the heat transfer tube 32 and is partitioned from the NG inlet chamber 33 by a partition plate 35. The upstream end of the third connecting pipe 53 is connected to the NG outlet chamber 44 of the water cooling unit E4, and the downstream end is connected to the NG inlet chamber 33 of the natural gas heating unit E3.

The heat transfer tube 32 is for flowing NG flowing out from the water cooling unit E4, extends from the pipe inlet 32A to one side in the horizontal direction, and then bends, and from the bent portion toward the pipe outlet 32B to the other side in the horizontal direction. It has an extending shape. Water W1 before flowing into the intermediate medium evaporation section E1 flows into the space inside the shell 31, and the water W1 flows out of the shell 31 from the water outlet 31B provided at the lower part of the shell 31.

In the natural gas heating unit E3, the NG flowing out from the water cooling unit E4 (NG outlet chamber 44) flows into the NG inlet chamber 33 through the third connecting pipe 53, and then flows into the heat transfer tube 32 from the pipe inlet 32A. Inflow. Then, the NG is heated by recovering heat from the water W1 flowing into the shell 31 in the process of flowing through the heat transfer tube 32 from the tube inlet 32A toward the tube outlet 32B, and flows out to the NG outlet chamber 34.

<Gas turbine combined power generator>
Next, FIG. 2 mainly describes the configuration of the gas turbine combined power generation device 2 that generates power using the NG generated in the liquefied natural gas vaporizer 1 (NG flowing out from the NG outlet chamber 34 of the natural gas heating unit E3) as fuel. It will be explained with reference to. As shown in FIG. 2, the gas turbine combined power generation device 2 includes a cooler 81, an air compressor 82, a gas turbine 83, an exhaust heat recovery boiler 84, a steam turbine 86, a gas turbine generator 85, and the like. Mainly has.

The air compressor 82 compresses the air cooled by the cooler 81. The gas turbine 83 is NG burned by the compressed air discharged from the air compressor 82, and is rotationally driven by the combustion gas generated by the combustion.

The exhaust heat recovery boiler 84 has a first flow path 84A through which the combustion gas flowing out from the gas turbine 83 flows, and a second flow path 84B through which water flows, and heats the combustion gas and water. Evaporate the water by exchanging. The steam turbine 86 is rotationally driven by the steam generated in the exhaust heat recovery boiler 84. The gas turbine generator 85 is connected to the gas turbine 83 and the steam turbine 86, and converts the rotational energy of the gas turbine 83 and the steam turbine 86 into electric energy.

<Water circulation mechanism>
Next, the configuration of the water circulation mechanism 3 that circulates the water W1 between the liquefied natural gas vaporizer 1 and the gas turbine combined power generation device 2 will be described with reference to FIGS. 1 and 2. As shown in FIG. 1, the water circulation mechanism 3 includes a chilled water supply flow path 62 for supplying water W1 (cold water) from the liquefied natural gas vaporizer 1 to the cooler 81, and water from the cooler 81 to the liquefied natural gas vaporizer 1. It has a hot water supply flow path 63 for supplying W1 (hot water).

The chilled water supply flow path 62 is composed of pipes, and the upstream end is connected to the water outlet 41B of the shell 41 of the water cooling unit E4, and the downstream end is connected to the inlet of the first flow path 81A of the cooler 81. It is connected. As shown in FIG. 1, in the chilled water supply flow path 62, the chilled water tank 70 for storing the water W1 (cold water) flowing out from the water cooling unit E4 and the water W1 flowing out from the water cooling unit E4 are directed toward the cooler 81. The chilled water circulation pump 71 that sends out the water is arranged in order from the upstream side to the downstream side in the flow direction of the water W1. The cold water tank 70 may be omitted.

The hot water supply flow path 63 is composed of pipes, and the upstream end is connected to the outlet of the first flow path 81A of the cooler 81, and the downstream end is connected to the water inlet chamber 12 of the intermediate medium evaporation unit E1. Has been done. The hot water supply flow path 63 includes a backup warmer 72 that further heats the water W1 (hot water) flowing out of the cooler 81 with a heat source such as seawater, and a hot water tank 73 that stores the water W1 flowing out of the cooler 81. The hot water circulation pump 74 that sends out the water W1 flowing out from the cooler 81 toward the liquefied natural gas vaporizer 1 is arranged in order from the upstream side to the downstream side in the flow direction of the water W1. The backup warmer 72 and the hot water tank 73 may be omitted, respectively.

The water circulation mechanism 3 further has a hot water side branch flow path 63A. As shown in FIG. 1, the hot water side branch flow path 63A connects a portion P1 of the hot water supply flow path 63 on the downstream side of the hot water circulation pump 74 and a water inlet 31A of the shell 31 of the natural gas heating portion E3. It has a first flow path portion 63AA, and a second flow path portion 63AB that connects the water outlet 31B of the shell 31 and the portion P2 of the hot water supply flow path 63 downstream of the portion P1. .. With this configuration, a part of the water W1 (hot water) flowing through the hot water supply flow path 63 is separated from the portion P1 and passed through the space inside the shell 31 of the natural gas heating portion E3, and then the hot water is supplied at the portion P2. It can be merged with the water W1 flowing through the flow path 63.

With the above configuration, water W1 can be circulated between the liquefied natural gas vaporizer 1 and the cooler 81 through the cold water supply flow path 62 and the hot water supply flow path 63. On this circulation flow path, the water cooling unit E4 is arranged in series with the intermediate medium evaporation unit E1 on the downstream side of the intermediate medium evaporation unit E1.

<Cold water supply method>
Next, the cold water supply method according to the first embodiment of the present invention will be described. In the cold water supply method according to the present embodiment, the water W1 (cold water) flowing out from the water cooling unit E4 (shell 41) of the liquefied natural gas vaporizer 1 is used as the air for driving the gas turbine in the gas turbine combined power generation device 2. This is a method of supplying as cooling water.

First, by operating the hot water circulation pump 74, water W1 (hot water) is allowed to flow into the water inlet chamber 12 of the intermediate medium evaporation section E1 through the hot water supply flow path 63. At this time, a part of the water W1 is diverted from the portion P1 to the hot water side branch flow path 63A (first flow path portion 63AA), passed through the shell 31 of the natural gas heating portion E3, and then the water inlet chamber 12 It may be merged with the hot water supply flow path 63 on the immediate upstream side (site P2).

Next, the water W1 is allowed to flow into the heat transfer tube 11 from the water inlet chamber 12, and is circulated in the heat transfer tube 11 from the water inlet chamber 12 toward the water outlet chamber 13. At this time, heat exchange between the water W1 and the liquid intermediate medium M1 occurs through the tube wall portion of the heat transfer tube 11, and the water W1 recovers the cold heat from the liquid intermediate medium M1, for example, about 4 to 5 ° C. Is cooled to. Then, the cooled water W1 (cold water) flows out from the heat transfer tube 11 to the water outlet chamber 13.

Next, the water W1 flowing out of the water outlet chamber 13 is allowed to flow into the shell 41 of the water cooling unit E4 through the second connecting pipe 52. At this time, heat exchange between the water W1 and the NG occurs through the tube wall portion of the heat transfer tube 42, and the water W1 recovers the cold heat from the NG to be further cooled to a temperature lower than 4 to 5 ° C. Then, the cooled water W1 flows out from the water outlet 41B of the shell 41 into the cold water supply flow path 62.

Next, by operating the chilled water circulation pump 71, the water W1 cooled to a temperature lower than 4 to 5 ° C. by NG in the water cooling unit E4 is passed through the chilled water supply flow path 62 to the cooler 81 (first flow path 81A). Supply to. As a result, the air sucked into the second flow path 81B of the cooler 81 is cooled by the water W1 (cold water) flowing through the first flow path 81A.

As described above, the liquefied natural gas vaporizer 1 according to the present embodiment includes a water cooling unit E4 that cools the water W1 by utilizing the cold heat of NG generated in the liquefied natural gas vaporizer E2. As a result, as described below, the temperature of the water W1 (cold water) flowing out of the liquefied natural gas vaporizer 1 can be lowered to a temperature lower than 4 to 5 ° C. while suppressing icing in the liquefied natural gas vaporizer 1. it can.

That is, as described above, in the liquefied natural gas vaporizer 1, the liquid intermediate medium M1 is heated by the water W1 and evaporated, and the LNG is heated by the gaseous intermediate medium M2 to generate NG. Here, in the intermediate medium evaporation unit E1, the intermediate medium heat recovered from the water W1 changes its state from a liquid to a gas. That is, since the liquid intermediate medium M1 recovers heat from the water W1 as latent heat, the boundary film heat transfer coefficient on the outside of the heat transfer tube 11 (on the liquid intermediate medium M1 side) becomes large. Therefore, in the intermediate medium evaporation section E1, the tube wall temperature of the heat transfer tube 11 tends to decrease due to the influence of the liquid intermediate medium M1, and when the water W1 is lowered to a temperature lower than 4 to 5 ° C., the inner surface of the tube wall of the heat transfer tube 11 There is growing concern about icing in.

On the other hand, in the water cooling unit E4, NG recovers heat from the water W1 as sensible heat. That is, unlike the intermediate medium evaporation unit E1, the water cooling unit E4 does not change the state of the medium (NG) on the other side that exchanges heat with the water W1. Therefore, the boundary film heat transfer coefficient on the inside (NG side) of the heat transfer tube 42 becomes small, and therefore, it is possible to suppress an excessive decrease in the tube wall temperature of the heat transfer tube 42. Therefore, according to the liquefied natural gas vaporizer 1 according to the present embodiment, when there is a request for the water cooling unit E4 to cool the water W1 to a temperature lower than 4 to 5 ° C., the circulation amount of the water W1 is increased or Even if brine water or the like is not used as the water W1, icing on the outer wall surface of the heat transfer tube 42 can be suppressed. Further, by providing the water cooling unit E4 as a new heat exchange unit, the heat load in the other heat exchange units (intermediate medium evaporation unit E1, liquefied natural gas vaporization unit E2, and natural gas heating unit E3) can be reduced. Will also be possible.

(Embodiment 2)
Next, the configuration of the liquefied natural gas vaporizer 1A according to the second embodiment of the present invention will be described with reference to FIG. The liquefied natural gas vaporizer 1A according to the second embodiment basically has the same configuration as the liquefied natural gas vaporizer 1 according to the first embodiment and exhibits the same action and effect, but is heated by natural gas. It differs from the first embodiment in that the configuration of the part E3 is omitted.

As shown in FIG. 3, the liquefied natural gas vaporizer 1A according to the second embodiment is composed of three heat exchange units, an intermediate medium evaporation unit E1, a liquefied natural gas vaporization unit E2, and a water cooling unit E4. Such a liquefied natural gas vaporizer 1A can be used in applications where the supply of NG at room temperature is not required and the supply of NG at a low temperature of around 0 ° C. is required.

It should be understood that the embodiments disclosed as described above are exemplary in all respects and are not restrictive. The scope of the present invention is shown by the scope of claims rather than the above description, and it is intended to include all modifications within the meaning and scope equivalent to the scope of claims. Therefore, the scope of the present invention also includes the following embodiments.

In the first embodiment, the case where the water cooling unit E4 is configured by the fin-and-tube heat exchanger has been described, but the present invention is not limited to this. The water cooling unit E4 may be composed of, for example, a plate type heat exchanger or a fixed tube plate type heat exchanger. Further, the natural gas heating unit E3 may also be composed of a plate type heat exchanger or a fixed tube plate type heat exchanger.

Further, FIG. 1 shows a case where water W1 flows from the upper side to the lower side in the shells 31 and 41 of the natural gas heating unit E3 and the water cooling unit E4, but in the shells 31 and 41. Water W1 may flow from the lower side to the upper side. That is, the water inlet may be formed at the lower part of the shells 31 and 41, and the water outlet may be formed at the upper part of the shells 31 and 41, respectively.

Further, in FIG. 1, in each of the natural gas heating unit E3 and the water cooling unit E4, NG circulates inside the heat transfer tubes 32 and 42, and water W1 circulates outside the heat transfer tubes 32 and 42. Not limited to. That is, the water W1 may circulate inside the heat transfer tubes 32 and 42, and the NG may circulate outside the heat transfer tubes 32 and 42 (the space inside the shells 31 and 41).

In the first embodiment, a configuration in which a part of water W1 (warm water) is diverted to the natural gas heating unit E3 has been described, but the entire amount of water W1 (warm water) is distributed to the natural gas heating unit E3 and the intermediate medium evaporation unit E1. May be continuously distributed to.

In the first embodiment, the cooling of the gas turbine driving air in the gas turbine combined power generation device 2 has been described as an application in which the water W1 (cold water) flowing out from the water cooling unit E4 is used, but the present invention is not limited to this. For example, the cooled water W1 can be used for other purposes such as cooling heat exchangers and power generation cables used for cooling various facilities.

1,1A Liquefied natural gas vaporizer 2 Gas turbine combined power generation device E1 Intermediate medium evaporation part E2 Liquefied natural gas vaporization part E3 Natural gas heating part E4 Water cooling part M1 Liquid intermediate medium M2 Gas-like intermediate medium W1 Water

Claims (3)

A liquefied natural gas vaporizer
An intermediate medium evaporation section that evaporates at least a part of the liquid intermediate medium by heat exchange between the liquid intermediate medium and water.
A liquefied natural gas that vaporizes at least a part of the liquefied natural gas by exchanging heat between the gaseous intermediate medium generated by the evaporation of the liquid intermediate medium and the liquefied natural gas in the intermediate medium evaporation section. Vaporization department and
The heat transfer section transfers the natural gas generated by the vaporization of the liquefied natural gas in the liquefied natural gas vaporization section and the water cooled by heat exchange with the liquid intermediate medium in the intermediate medium evaporation section. A liquefied natural gas vaporizer comprising a water cooling unit that further cools the water by exchanging heat through the gas. A natural gas heating unit that heats the natural gas by exchanging heat between the natural gas that has exchanged heat with the water in the water cooling unit and the water that has not flowed into the intermediate medium evaporation unit. The liquefied natural gas vaporizer according to claim 1, further provided. A chilled water supply method for supplying the water flowing out from the water cooling unit of the liquefied natural gas vaporizer according to claim 1 or 2 as cooling water for gas turbine driving air in a gas turbine combined power generation device.

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