WO2022180812A1

WO2022180812A1 - Fuel vaporization equipment

Info

Publication number: WO2022180812A1
Application number: PCT/JP2021/007464
Authority: WO
Inventors: 知之五十嵐; 弘行臼井; 篤志神谷
Original assignee: 日揮株式会社
Priority date: 2021-02-26
Filing date: 2021-02-26
Publication date: 2022-09-01
Also published as: JPWO2022180812A1; TW202235767A

Abstract

[Problem] To provide a technique whereby equipment for vaporizing liquid fuel is used and cold seawater adjusted to the desired temperature is supplied to cold/heat-using equipment. [Solution] Fuel vaporization equipment that vaporizes liquid fuel, wherein an open rack vaporizer (1) vaporizes the liquid fuel using seawater, and a seawater supply line (301) supplies seawater to the open rack vaporizer (1). A cold seawater supply line (402) supplies cold/heat-using equipment (5) with cold seawater that has decreased in temperature due to heat exchange with liquid fuel in the open rack vaporizer (1), and a circulation line (401) adjusts the temperature of the cold seawater by resupplying some of the cold seawater to the open rack vaporizer (1). [Selected drawing] Figure 2

Description

Fuel vaporizer

The present invention relates to technology that utilizes cold energy obtained when liquefied fuel is vaporized.

In using liquefied natural gas (LNG), liquefied hydrogen, or other liquefied fuel, it is necessary to vaporize the liquefied fuel and supply it in the form of gas to the fuel consuming equipment.
As a type of equipment for vaporizing liquefied fuel, open rack vaporization vaporizes the liquefied fuel supplied inside the heat transfer tubes by flowing sea water as a heating medium along the outer surface of a panel composed of many heat transfer tubes. A device (ORV: Open Rack Vaporizer) is known.

On the other hand, in a liquefied fuel vaporization facility, the temperature of the heating medium decreases due to heat exchange with the liquefied fuel, so a technology has been proposed that utilizes the cold energy accumulated in the heating medium for temperature control in plant factories. (For example, Patent Documents 1 and 2).

However, in order to reduce environmental impact, there are restrictions on the minimum temperature of seawater that is discharged outside from the storage terminal where the liquid fuel is stored. In addition, while the temperature of sea water may change depending on the weather and season, the vaporization equipment should be operated to vaporize the liquefied fuel at the required flow rate. Therefore, the temperature of the seawater flowing out from the ORV may change depending on these conditions.
For these reasons, the temperature of low-temperature seawater (cold seawater) discharged from the ORV may not match the temperature required by cold heat utilization equipment such as plant factories.

JP 2014-31964 A Registered Utility Model No. 3209642

The present invention uses a liquefied fuel vaporization facility to provide a technology for supplying cold seawater adjusted to a desired temperature to cold heat utilization facilities.

The present invention is a fuel vaporization facility for vaporizing liquefied fuel,
an open rack vaporizer that vaporizes the liquefied fuel by flowing seawater along the outer surfaces of the plurality of heat transfer tubes to which the liquefied fuel is supplied;
a seawater supply line for supplying seawater toward the open rack vaporizer;
A cold seawater supply line that supplies cold seawater, which is used for vaporizing the liquefied fuel in the open rack vaporizer and whose temperature has been lowered by heat exchange with the liquefied fuel, to cold heat utilization equipment that uses the cold heat of the cold seawater. When,
a circulation line for resupplying a portion of the cold sea water discharged from the open rack vaporizer to the open rack vaporizer to reduce the temperature of the cold sea water to a preset temperature. It is characterized by

The fuel vaporization facility may have the following features.
(a) The cold energy utilization equipment is a culture tank that uses the cold heat of the cold sea water to adjust the temperature of the water for cultivating fish and shellfish, or the cold heat is used to create a plant growing atmosphere, growing soil, or culture water. It shall be a plant factory that performs at least one temperature control of
(b) the liquefied fuel is liquefied natural gas or liquefied hydrogen;
(c) a cold seawater pit for receiving cold seawater discharged from the open rack vaporizer, the cold seawater supply line supplying the cold seawater in the cold seawater pit to the cold heat utilization equipment, and the circulation line and resupplying the cold seawater in the cold seawater pit to the open rack vaporizer.
(d) is interposed in the seawater supply line, into which seawater flowing through the seawater supply line flows, is provided adjacent to the cold seawater pit via a partition wall, and overflows from the upper end of the partition wall; A seawater supply pit configured to receive the cold seawater is provided, and an upper end surface of the partition wall, which is a region where cold seawater flows from the cold seawater pit to the seawater supply pit, constitutes the circulation line. and increasing or decreasing the flow rate of the seawater flowing into the seawater supply pit to increase or decrease the flow rate of the cold seawater resupplied from the cold seawater pit to the open rack vaporizer via the seawater supply pit, To regulate the temperature of cold sea water.
(e) The open rack vaporizer includes a receiving tank portion that receives seawater after flowing along the outer surface of the heat transfer tube, and the cold seawater supply line supplies the cold seawater in the receiving tank portion to the cold heat utilization equipment. and the circulation line re-supplies the cold seawater in the receiving tank portion to the open rack vaporizer.
(f) An uncooled pre-cooled seawater supply line is provided to supply seawater that has not been cooled by the open rack vaporizer toward the cold heat utilization equipment.

According to the present invention, since a circulation line is provided for resupplying part of the cold seawater whose temperature has been lowered by heat exchange for vaporizing liquefied fuel in the open rack vaporizer to the open rack vaporizer, cold heat utilization The temperature of the cold seawater supplied to the facility can be adjusted to the desired temperature.

It is a block diagram of the conventional LNG vaporization equipment. 1 is a configuration diagram of an LNG vaporization facility according to an embodiment; FIG. It is a block diagram of the LNG vaporization equipment which concerns on 2nd Embodiment. It is a block diagram of the LNG vaporization equipment which concerns on 3rd Embodiment. It is a block diagram of the LNG vaporization equipment which concerns on 4th Embodiment.

Before showing the configuration of the fuel vaporization equipment according to the embodiment, a configuration example of the conventional fuel vaporization equipment will be described with reference to FIG. In each figure shown below, LNG vaporization equipment for vaporizing liquefied natural gas (LNG) will be described as an example of liquefied fuel.

The LNG vaporization equipment vaporizes LNG stored in an LNG tank 2 with an open rack vaporizer (ORV) 1 and supplies the fuel gas after vaporization to a consumer through a fuel gas supply line 101 .
The ORV 1 causes seawater to flow down along the outer surface of a panel 11 composed of a large number of heat transfer tubes to which LNG from the LNG tank 2 is supplied, and vaporizes the LNG through heat exchange with the seawater to obtain fuel gas. with configuration.

The ORV 1 shown in FIG. 1 uses seawater (for example, 20° C.) taken in by the water intake pump 31 as seawater for vaporizing LNG.
As a specific configuration example, seawater taken by the water intake pump 31 is supplied toward the ORV seawater supply line 301 connected to the ORV1. The seawater supply flow rate is adjusted using a flow rate detector 322 and a flow rate control valve 321 provided in the ORV seawater supply line 301 . The seawater used to vaporize the LNG is discharged through the ORV drain line 302 towards the water outlet.

In the LNG vaporization equipment having the above-described configuration, seawater with a lowered temperature is obtained by heat exchange with LNG in the ORV 1, and the cold energy of this seawater can be utilized in various cold energy utilization equipment.
Cold energy is used in equipment that uses cold energy to control the temperature of aquaculture water in fish and shellfish culture tanks, and to control the temperature of at least one of the atmosphere for growing plants, the soil for growing plants, or the temperature of culture water in a plant factory. A case can be exemplified.

For example, the water for cultivating salmon is preferably less than 20°C, and the water for cultivating abalone is preferably less than 25°C. In addition, it is preferable that the strawberry-growing soil and the supply water supplied to the soil have a temperature of less than 15°C. As described above, in cold energy utilization equipment, there is a suitable temperature according to the purpose of use of each cold energy.

However, in order to reduce the impact on the environment, there are restrictions on the lower limit temperature of the seawater discharged to the outside. On the other hand, since the ORV 1 uses a large amount of seawater, it may be difficult to use the entire amount of seawater discharged from the ORV 1 in cold heat utilization equipment.

Therefore, even if part of the seawater discharged from ORV1 is supplied to cold heat utilization equipment, most of the remaining seawater must be discharged to the outside as it is. If a large amount of low-temperature seawater is discharged, there is a risk that the temperature of the seawater discharged to the water discharge port will fall below the permissible temperature. Therefore, in the conventional LNG vaporization facility shown in FIG. 1, the actual situation was that the seawater temperature at the outlet of the ORV 1 could only be lowered to about 17° C., for example.

In addition, the temperature of sea water may change depending on the weather and season. On the other hand, in the LNG vaporization equipment, the highest priority is given to the operation of vaporizing LNG at a flow rate that meets the demand from the consumer side. Therefore, when the temperature of the supplied seawater changes, it may be difficult to keep the temperature of the seawater discharged from the ORV 1 at the temperature required by the cold heat utilization equipment.

As described above, in the conventionally configured LNG vaporization equipment, it was sometimes difficult to stably supply cold seawater at a temperature required for cold heat utilization equipment throughout the year.
The LNG vaporization equipment according to the present embodiment has a configuration that can stably supply cold seawater at a temperature required by cold heat utilization equipment while suppressing the impact on the environment in response to the above problems. I have.

Hereinafter, an example of the overall configuration of the LNG vaporization equipment according to the embodiment will be described with reference to FIG. The LNG vaporization equipment shown in FIG. 2 has a configuration capable of supplying part of the cold seawater discharged from the ORV 1 toward the cold heat utilization equipment 5 consisting of a culture tank and a plant factory.
2 to 5 described below, the same reference numerals as those shown in FIG. 1 are attached to the same components as those described using FIG.

In the LNG liquefaction facility shown in FIG. 2, the passage through which the seawater discharged from the ORV 1 flows is the ORV drainage line 302a for discharging cold seawater toward the water outlet and the cold seawater supplied to the cold heat utilization equipment 5. It branches to the flowing cold seawater pit line 302b.
The ORV drain line 302a discharges cold sea water towards the water outlet. On the other hand, a cold seawater pit 41 is provided on the downstream side of the cold seawater pit line 302b, and the cold seawater supplied to the cold heat utilization equipment 5 is received in this cold seawater pit 41.

A cold seawater supply line 402 is provided between the cold seawater pit 41 and the cold heat utilization equipment 5 to supply cold seawater to the cold heat utilization equipment 5 . The cold seawater that has flowed into the cold seawater pit 41 is supplied to the cold heat utilization equipment 5 via the cold seawater supply line 402 by the liquid feed pump 44 provided on the upstream side of the cold seawater supply line 402 . The flow rate of cold seawater supplied to the cold-heat utilization equipment 5 is adjusted using a flow rate detector 432 and a flow rate control valve 431 provided in the cold seawater supply line 402 . In addition, the cold seawater supply line 402 is provided with an on-off valve 433 , which can supply and stop the cold seawater to the cold heat utilization equipment 5 .

Further, from the above-described cold seawater supply line 402, a circulation line 401 for resupplying cold seawater in the cold seawater pit 41, that is, part of the cold seawater discharged from the ORV1 to the ORV1 is branched. The circulation line 401 branches off from the cold seawater supply line 402 at a position on the upstream side of the on-off valve 433 , and its downstream end joins the ORV seawater supply line 301 . The ORV seawater supply line 301 corresponds to the seawater supply line of this embodiment.

The resupply flow rate (circulation flow rate) of cold seawater to the ORV 1 is set in advance by using the temperature detection unit 422 and the flow control valve 421 provided in the cold seawater pit 41. The target temperature (for example, 15° C.) is adjusted. The target temperature of cold seawater is set to the temperature of cold seawater required by the cold heat utilization equipment 5 . Further, the circulation line 401 is provided with an on-off valve 423, which can execute and stop the resupply of cold seawater to the ORV1.

According to the configuration described above, by resupplying cold seawater to ORV1 via circulation line 401, the temperature of seawater supplied to ORV1 is decreases (eg 18°C).
At this time, from the viewpoint of LNG vaporization in the ORV 1, the seawater supply flow rate to the ORV 1, that is, The total flow rate of the seawater supply flow rate supplied through the circulation line 401 and the circulation flow rate of the cold seawater supplied via the circulation line 401 may be ensured.

The operation of the LNG liquefaction facility having the configuration described above will be explained. As in the conventional LNG liquefaction facility, in the ORV 1, seawater supplied via the ORV seawater supply line 301 is caused to flow down along the outer surface of the panel 11 to vaporize the LNG to obtain fuel gas. A part of the cold seawater whose temperature has been lowered by heat exchange with LNG is received in the cold seawater pit 41 via the cold seawater pit line 302b. Also, the remaining cold seawater is discharged through the ORV drain line 302a toward the outlet.

Of the cold seawater that has flowed into the cold seawater pit 41, the portion to be supplied to the cold heat utilization equipment 5 is supplied to the cold heat utilization equipment 5 via the cold seawater supply line 402 while adjusting the flow rate according to the consumption amount.
On the other hand, the circulation flow rate of the cold seawater resupplied to the ORV 1 via the circulation line 401 is adjusted according to the temperature of the cold seawater in the cold seawater pit 41 . That is, an operation control range centering on the target temperature of the cold seawater is set, and when the temperature of the cold seawater in the cold seawater pit 41 exceeds the upper limit of the operation control range, the circulation flow rate is increased, Decrease the temperature of the seawater supplied to ORV1. Moreover, when the temperature of the cold seawater in the cold seawater pit 41 falls below the lower limit value of the operation control range, the circulation flow rate is decreased to raise the temperature of the seawater supplied to the ORV1. As a result, it is possible to supply cold seawater with a stable temperature within the operation control range to the cold heat utilization equipment 5 .

The flow rate of cold sea water flowing into the cold sea water pit 41 via the cold sea water pit line 302b is adjusted to balance the total flow rate of the supply flow rate to the cold heat utilization equipment 5 and the circulation flow rate to the ORV1.
In addition, when stopping the supply of cold seawater to the cold heat utilization equipment 5, the on-off

valves

433 and 423 are closed to stop the discharge and circulation of the cold seawater, and the ORV 1 is discharged via the ORV drainage line 302a. The entire amount of seawater is discharged to the outside.

In the LNG vaporization facility shown in FIG. 2, the temperature of the cold seawater discharged to the outside via the ORV drainage line 302a also decreases in accordance with the temperature of the cold seawater supplied to the cold heat utilization equipment 5. However, in the LNG vaporization facility, part of the cold seawater is resupplied to the inlet side of ORV1. Therefore, the flow rate of cold seawater discharged outside the cold seawater circulation system including the ORV 1 and the cold seawater pit 41 (that is, the flow rate of seawater newly supplied from the upstream side of the ORV seawater supply line 301) is 1 is significantly less than the conventional LNG vaporization facility described with .

The inventors have found that, in comparison with the flow rate of seawater discharged from the ORV drainage line 302 in the conventional LNG vaporization facility shown in FIG. It is understood that the flow rate can be reduced to about 20 to 50%.
Furthermore, since part of the cold seawater discharged out of the circulation system is supplied toward the cold heat utilization equipment 5, the flow rate of the cold seawater discharged via the ORV drainage line 302a is even smaller. Therefore, even if the temperature of the cold seawater discharged through the ORV drainage line 302a drops to 15° C., the total amount of cold seawater discharged is small, and the environment can be maintained in a small state.

The LNG vaporization equipment according to this embodiment has the following effects. A circulation line is provided for resupplying part of the cold seawater whose temperature has been lowered by heat exchange for vaporizing the liquefied fuel in the ORV1 to the ORV1. temperature can be adjusted.
Further, by resupplying cold seawater to the ORV 1, the flow rate of the cold seawater discharged to the outside can be reduced, and the influence of the cold seawater on the environment can be reduced.

Next, variations of the LNG vaporization equipment according to the embodiment will be described with reference to FIGS. 3 to 5. FIG.
FIG. 3 shows an example in which a cold seawater supply line pump 44b for the cold seawater supply line 402 and a circulation line pump 44a for the circulation line 401 are provided independently for the cold seawater pit 41. FIG. With this configuration, it is possible to increase the degree of freedom in adjusting the supply flow rate of cold seawater to the cold heat utilization equipment 5 and the circulation flow rate of cold seawater to the ORV 1 .

Also, FIG. 3 shows an example in which an uncooled seawater supply line 403 is provided for supplying part of the uncooled seawater discharged from the flow control valve 431 toward the cold heat utilization equipment 5 . The uncooled seawater supply line 403 branches off from the ORV seawater supply line 301 and is connected to the cold heat utilization facility 5 to supply relatively warm seawater compared to cold seawater. The seawater supply flow rate is adjusted using a flow rate detector 452 and a flow rate control valve 451 provided in the uncooled seawater supply line 403 .

With the above configuration, cold seawater is supplied to the cold heat utilization equipment 5 via the cold seawater supply line 402 during periods when the temperature of the seawater taken in by the water intake pump 31 is high (for example, in summer). Then, during a period when the temperature of the seawater to be taken in is low (for example, in winter), instead of supplying cold seawater from the cold seawater supply line 402, or in parallel, the flow rate control valve 431 is supplied via the uncooled seawater supply line 403 It can also supply relatively warm sea water discharged from the

Next, FIG. 4 shows a configuration example in which cold seawater is circulated using pits 51a and 52b instead of the circulation line 401 composed of the pipes shown in FIGS.
In the LNG vaporization facility shown in FIG. 4, an ORV seawater supply pit 41b into which seawater flowing through the upstream ORV seawater supply line 301a flows is interposed between the ORV

seawater supply lines

301a and 301b. The ORV seawater supply pit 41b is provided adjacently via a partition wall 411 to the cold seawater pit 41a into which all the cold seawater discharged from the ORV 1 flows via the cold seawater pit line 302b. The cold seawater pit 41a is connected to a pit drain line 302c through which cold seawater is discharged toward the outlet.

The partition wall 411 is configured to have a height that allows the cold seawater that cannot be accommodated in the cold seawater pit 41a to overflow toward the ORV seawater supply pit 41b through the upper end of the partition wall 411. That is, the upper end surface of the partition wall 411, which is the area where the cold seawater flows from the cold seawater pit 41a to the ORV seawater supply pit 41b, constitutes a circulation line through which the cold seawater to be resupplied to the ORV1 flows.

An ORV supply pump 33 is provided in the ORV seawater supply pit 41b, and seawater is supplied to the ORV 1 via the ORV seawater supply line 301. A flow control valve 321a is provided in the ORV seawater supply line 301a that supplies seawater from the ORV seawater supply line 301a to the ORV seawater supply pit 41b. The flow control valve 321a controls the cold seawater pit so that the temperature of the seawater in the ORV seawater supply pit 41b approaches the target temperature based on the temperature detection result of the temperature detection unit 323 that detects the seawater temperature in the ORV seawater supply pit 41b. Increase or decrease the flow rate of seawater flowing into 41a.

That is, as the temperature of the cold seawater flowing from the cold seawater pit 41a into the ORV seawater supply pit 41b rises, the temperature of the seawater in the ORV seawater supply pit 41b rises above the upper limit of the operation control range set around the target temperature. If it exceeds, the degree of opening of the flow control valve 321a is increased to increase the flow rate of seawater. In accordance with this, the ORV supply pump 33 is used to increase the flow rate of seawater supplied to the ORV 1 .

This operation increases the flow rate of cold seawater discharged from the ORV 1, and increases the circulation amount of cold seawater flowing from the cold seawater pit 41a to the ORV seawater supply pit 41b. As a result, the temperature of the cold seawater flowing into the cold seawater pit 41a decreases, and the temperature of the seawater in the ORV seawater supply pit 41b also approaches the target temperature. The amount of cold seawater in the ORV seawater supply pit 41b and the cold seawater pit 41a is kept constant, for example, by adjusting the amount of cold seawater discharged through the pit drain line 302c.

On the other hand, when the temperature of the cold seawater flowing from the cold seawater pit 41a to the ORV seawater supply pit 41b drops and the temperature of the seawater in the ORV seawater supply pit 41b falls below the lower limit value of the operation control range, the flow rate is adjusted. The degree of opening of the valve 321a is reduced to reduce the flow rate of seawater received. In accordance with this, the ORV supply pump 33 is also used to reduce the flow rate of seawater supplied to the ORV 1 .

This operation reduces the flow rate of cold seawater discharged from the ORV 1, and reduces the circulation amount of cold seawater flowing from the cold seawater pit 41a to the ORV seawater supply pit 41b. As a result, the temperature of the cold seawater flowing into the cold seawater pit 41a decreases, and the temperature of the seawater in the ORV seawater supply pit 41b approaches the target temperature. Also in this case, for example, the amount of cold seawater in the ORV seawater supply pit 41b and the cold seawater pit 41a is kept constant by adjusting the amount of cold seawater discharged through the pit drain line 302c.

Next, FIG. 5 shows a pump for sending cold seawater to the cold seawater supply line 402 and the circulation line 401 for the ORV pit 12 provided in the ORV 1 instead of the cold seawater pit 41 shown in FIGS. An example in which 44a and 44b are provided is shown. The ORV pit 12 serves to receive seawater after flowing along the outer surface of the panel 11 that exchanges heat between LNG and seawater, and is provided in the ORV1.

In the example shown in FIG. 5, for the circulation line pump 44a, a circulation line 401 for resupplying the cold seawater in the ORV pit 12 to the ORV 1 and discharging the cold seawater toward the water outlet. A pit drainage line 302c for On the other hand, cold seawater is supplied to the cold heat utilization equipment 5 through a cold seawater supply line 402 using a cold seawater supply line pump 44b, which is the same as the LNG vaporization equipment shown in FIG. .

The LNG vaporization equipment according to each embodiment described above with reference to FIGS. 2 to 5 may be used as a hydrogen vaporization equipment for vaporizing liquefied hydrogen, which is a liquid fuel.
Also, cold heat utilization equipment to which cold seawater is supplied from the fuel vaporization equipment of this example is not limited to the aquaculture layer or plant factory described above. For example, cold seawater may be supplied to coolers such as chemical plants and petroleum refining plants.

1 ORV
301, 301a, 301b
Seawater supply line 401 Circulation line 402 Cold seawater supply line 5 Cold heat utilization equipment

Claims

A fuel vaporization facility for vaporizing liquefied fuel,
an open rack vaporizer that vaporizes the liquefied fuel by flowing seawater along the outer surfaces of the plurality of heat transfer tubes to which the liquefied fuel is supplied;
a seawater supply line for supplying seawater toward the open rack vaporizer;
A cold seawater supply line that supplies cold seawater, which is used for vaporizing the liquefied fuel in the open rack vaporizer and whose temperature has been lowered by heat exchange with the liquefied fuel, to cold heat utilization equipment that uses the cold heat of the cold seawater. When,
a circulation line for resupplying a portion of the cold sea water discharged from the open rack vaporizer to the open rack vaporizer to reduce the temperature of the cold sea water to a preset temperature. A fuel vaporization facility characterized by:
The cold energy utilization equipment is a culture tank that uses the cold energy of the cold sea water to adjust the temperature of water for cultivating fish and shellfish, or at least one of a plant growing atmosphere, a growing soil, and a culture water that uses the cold energy. 2. The fuel vaporization facility according to claim 1, wherein the plant factory performs two temperature controls.
The fuel vaporization facility according to claim 1, wherein the liquefied fuel is liquefied natural gas or liquefied hydrogen.
A cold seawater pit is provided to receive cold seawater discharged from the open rack vaporizer, the cold seawater supply line supplies the cold seawater in the cold seawater pit to the cold heat utilization equipment, and the circulation line is the cold water. 2. The fuel vaporization facility according to claim 1, wherein cold seawater in a seawater pit is resupplied to said open rack vaporizer.
The cold seawater is interposed in the seawater supply line, into which the seawater flowing through the seawater supply line flows, is provided adjacent to the cold seawater pit via a partition wall, and overflows from the upper end of the partition wall. a seawater supply pit configured to receive a seawater supply pit, and an upper end surface of the partition wall, which is a region where cold seawater flows from the cold seawater pit to the seawater supply pit, constitutes the circulation line;
By increasing or decreasing the flow rate of the seawater flowing into the seawater supply pit, the flow rate of cold seawater resupplied from the cold seawater pit to the open rack vaporizer via the seawater supply pit is increased or decreased, 2. The fuel vaporization system according to claim 1, characterized by adjusting the temperature of the .
The open rack vaporizer includes a receiving tank portion that receives seawater after flowing along the outer surface of the heat transfer tube, and the cold seawater supply line supplies cold seawater in the receiving tank portion to the cold heat utilization equipment, 2. The fuel vaporization equipment according to claim 1, wherein the circulation line re-supplies the cold seawater in the receiving tank to the open rack vaporizer.
2. The fuel vaporization facility according to claim 1, further comprising an uncooled pre-seawater supply line for supplying seawater that has not been cooled by the open rack vaporizer toward the cold heat utilization facility.