KR20130133900A - Regasification-capable ngh transportationship, and ngh regasification method in ngh transportation ship - Google Patents

Abstract

NGH cargo warehouse 10, a heat exchanger 22 for supplying heat to the circulating water, and a circulation pump 21 for circulating the circulating water between the NGH cargo warehouse 10 and the heat exchanger 22. In addition, the gas discharge pipe 11 and the circulating water arithmetic unit 13 is installed on the upper part of the NGH cargo storage 10, and the NGH cargo storage (10) from the opening 16a inside the NGH cargo storage 10; A circulating water dropping pipe 16 for guiding the circulating water in 10) to the circulating water pipe 18 via a drain pipe 17 disposed below the bottom of the NGH cargo hold 10 is configured. As a result, the NGH pellets in the NGH cargo hold 10 of the NGH (natural gas hydrate) transport ship 1 can be stabilized with a simple configuration and regasified with good efficiency.

Description

Re-gasification NGH transport ship, and NGH regasification method in NGH transport ship {REGASIFICATION-CAPABLE NGH TRANSPORTATIONSHIP, AND NGH REGASIFICATION METHOD IN NGH TRANSPORTATION SHIP}

The present invention provides a regasifiable NGH transporter capable of efficiently regasifying NGH mounted on a dock of an NGH (natural gas hydrate) transporter with a simple configuration using circulating water, and an NGH gasification method in an NGH transporter. Regarding

The NGH transporter in charge of the sea transport of natural gas hydrate (hereinafter referred to as NGH), on the premise of regasification of landed NGH pellets on land, and the NGH transporter equipped with a mechanical unloading device for transporting NGH, and on board On the premise of discharging the regasified gas, there is a regasification NGH transport ship (NGH regas transport ship) equipped with a regasification facility on board the NGH transport ship.

This regasification NGH transport ship requires re-gasification facilities for NGH on board, but it is not necessary to equip the ship with a mechanical unloading device for NGH unloading, and also to install an NGH storage facility or regasification facility at a landing site. The advantage is that there is no need. For this reason, a regasification NGH transport ship is expected as a ship which plays an important role in both transportation and regasification when using NGH in a landing place where there is no space to install these facilities.

As an example of the ship which regasses NGH in this ship, for example, as described in Unexamined-Japanese-Patent No. 2008-126830, although it is not a ship which lands NGH, For example, the NGH tank which stored NGH, It is equipped with an NGH decomposing device that generates fuel gas by decomposing NGH supplied from the NGH tank. The fuel gas generated by the NGH gasifier is used to generate electric power by a gas engine generator. A driving ship has been proposed.

The cracking device of this vessel is to return the NGH cracking tank and hot water for cracking the NGH to the NGH tank in the NGH cracking tank and spray it from above the NGH pellets stored on the net. It extracts from the gas discharge port installed above the tank, and supplies it to a gas engine generator. On the other hand, the decomposed NGH decomposed water passes through a net disposed under the NGH decomposing tank, is separated from the NGH pellet, is taken out of a drain provided below the NGH decomposing tank, and is heated by a water heater or by heat exchange with seawater. After elevated, it is used as hot water for NGH decomposition.

However, in this ship, it is necessary to install an NGH decomposition device for regasification separately from the NGH tank, and if it is to be applied to an NGH transport ship, it is necessary to regasify in large quantities at the time of discharging. There is a problem that there is a need to increase the gasification capacity, the size of the NGH decomposer is enlarged, and the need to reduce the volume of the NGH tank for transportation occurs.

Prior art literature

Patent literature

Patent Document 1: Japanese Patent Application No. 2008-126830

In order to avoid the above problem, in a regasificationable NGH transporter which regasifies on the ship side, it is considered to regasify in the NGH cargo hold instead of returning the NGH in the NGH cargo hold to the regasification apparatus. This means that space for regasification apparatus, piping and equipment, and equipment for conveyance from the NGH cargo hold to the regasification apparatus are unnecessary, which is efficient.

In addition, in order to quickly regasify in the NGH cargo hold, it is preferable to melt the NGH pellets by applying a high temperature, but in consideration of the operation cost and the reduction of carbon dioxide accompanying the high heat generation, in the case of an NGH transportable vessel that can be regasified, Since there is seawater, it has been found that the heat source used for gasification is preferably circulating water (fresh water) obtained by heat exchange with seawater.

However, when a large amount of pellets in the NGH cargo hold are supplied with circulating water at a temperature of about the sea water temperature from the top of the NGH pellet layer, it is impossible for the circulating water to penetrate into the lower part of the NGH pellet layer. There is a possibility that the circulating water stays in the water and freezing occurs in a part of the circulating water. If the extent of this freezing is wide, there is a possibility that the drainage path cannot be secured and the level of the circulating water rises, and the circulating water in the NGH cargo hold may overflow. Therefore, in a state where the circulation water is likely to overflow, since the circulation water, which is a heat source for decomposing NGH, cannot be circulated smoothly, there is a problem that it is difficult to stabilize the NGH pellets and efficiently regasify it.

The present invention has been made in view of the above-described situation, and an object thereof is to regasify the NGH pellets in the NGH cargo hold of an NGH (natural gas hydrate) transport ship, which can be regasified efficiently and efficiently with a simple configuration. An NGH transport ship and the NGH regasification method in an NGH transport ship are provided.

The regasifiable NGH (natural gas hydrate) transport ship of the present invention for achieving the above object is an NGH cargo hold for accommodating NGH pellets, a heat exchanger for supplying heat to the circulating water serving as a heat source for decomposing the NGH pellets, and circulation A circulation water pipe and a circulation pump for circulating water between the NGH cargo hold and the heat exchanger are provided, and at the upper portion of the NGH cargo hold, a gas discharge pipe for decomposing gas of NGH pellets and a circulation water can be sprayed. A circulating water sprinkler is provided, and the purified water in the NGH cargo hold is disposed in the NGH cargo hold via the drain pipe disposed below the bottom of the NGH cargo hold. It is configured by installing a circulating water drop pipe leading to the circulating water pipe.

When the circulating water is sprinkled from the top to the NGH pellet layer, the circulating water, which is a heat source that decomposes the NGH pellets introduced from the upper portion of the cargo hold of the NGH pellets, freezes in the NGH pellet layer and hardly penetrates into the NGH pellet layer. In such a case, the circulated water may be passed through a circulating drip tube (transfusion) installed inside the NGH cargo hold and lowered below the bottom of the NGH cargo hold. It is possible to lead from the drain pipe connected to the lower part of the pipe to the external circulation water pipe of the NGH cargo hold.

In addition, the circulating water dropping pipe is configured to drop the opening so that the circulating water at the top of the NGH pellet layer can be introduced into the circulating water dropping pipe even when the NGH pellet layer is degraded due to the decomposition of the NGH pellets in the NGH cargo hold. Install at multiple positions in the vertical direction of the pipe.

Further, in the regasifying NGH transport ship, the heat exchanger and the circulation pump are arranged in a compartment provided between the engine compartment and the NGH cargo hold in front of the engine compartment, and the engine compartment or the electric motor adjacent to the compartment. If the circulation pump is configured to be driven by a drive source provided in a non-hazardous compartment of the chamber, this will cause the circulation pump to be driven in an engine room that is an explosion-proof area (non-hazardous area). It is possible to use the drive source of a specification.

In the regasification of the NGH transport ship, when the decomposed water generated in the regasification of NGH is configured to be used as the circulating water, the initial amount of the circulating water is kept in a small amount.

In the regasification of the NGH transporter, the gaseous NGH is regasified at the landing place and the decomposed water generated by the regasification is returned to the proper land, so that the ballast sailing to the proper land without loading the seawater ballast is performed. It is possible. As a result, since the dedicated ballast tank and the ballast water treatment apparatus are unnecessary, the effective use of the space inside the ship can be realized and the cost can be reduced.

In the re-gasification of the NGH transport ship, if the NGH cargo hold has a pressure resistant structure and is configured to increase the gasification pressure in the NGH cargo hold, the gasified gas in the NGH transport ship meets the demand value of the demand side. Although it is compressed and supplied by the gas compressor, by raising the gasification pressure in NGH cargo hold in this way, compared with gasification in the vicinity of atmospheric pressure, the pressure rise in a gas compressor can be made small and the size of a gas compressor can be made small, and power It is possible to make less.

Thus, in the NGH regasification method in the NGH transport ship of the present invention for achieving the above object, in the upper portion of the NGH cargo hold containing the NGH pellets, the circulating water that is a heat source for decomposing the NGH pellets is sprinkled, and the circulation The NGH decomposition gas generated by decomposition of water is derived from the gas discharge pipe installed at the upper portion of the NGH cargo hold, and the circulating water in the NGH cargo hold is introduced into the circulating water dropping pipe from the opening to the bottom of the NGH cargo hold. Rather, the circulating water derived from the drain pipe arranged below is circulated to the heat exchanger by the circulating water pipe and the circulating pump, and the heat exchanger circulates between the circulating water and the sea water in the heat exchanger. The temperature of the water is increased, and the water is sprayed again from the top of the NGH cargo hold.

When the circulating water is sprinkled from the top to the NGH pellet layer, the circulating water, which is a heat source for decomposing the NGH pellets injected from the upper part of the NGH cargo hold, freezes in the NGH pellet layer and hardly penetrates into the NGH pellet layer, and the upper part of the NGH pellet layer. In such a case, the circulating water may be allowed to pass through the circulating water descent pipe provided inside the NGH cargo hold, and then descend below the bottom of the NGH cargo hold and be connected to the lower part of the circulating water descent pipe. It is possible to lead from piping to piping for external circulating water in NGH cargo holds.

According to the regasificationable NGH transporter of the present invention and the NGH regasification method in the NGH transporter, the circulating water, which is a heat source for decomposing NGH, freezes in the NGH pellet layer and hardly penetrates into the NGH pellet layer. Although it may stay in the upper part, even in this case, the circulated water is allowed to pass down the lower part of the NGH cargo hold by passing through the vertical circulating water drip pipe (transfusion) installed inside the NGH cargo hold. It is possible to lead from the drain pipe connected to the lower part of the circulating water drop pipe to the external circulating water pipe of the NGH cargo hold.

As a result, since the circulating water sprinkled at the upper portion of the NGH cargo hold through the circulating water reinforcing pipe is drained to the drain pipe at the bottom of the NGH cargo hold, the circulating water can be prevented from overflowing by staying at the upper part of the NGH pellet layer. As a result, the NGH mounted on the NGH transport ship can be efficiently regasified with a simple structure using circulating water.

In addition, the re-gasification NGH transporter of the present invention, and the NGH regasification method in the NGH transporter, even in the NGH transporter equipped with a mechanical unloading device that lands in NGH pellets without regasification, the mechanical unloading device and the land It can be used for emergency gasification if the landing and unloading device on the side has failed.

1 is a side cross-sectional view showing the configuration of a regasifiable NGH transport ship of an embodiment according to the present invention.
FIG. 2 is a plan view showing the configuration of the regasifiable NGH transport ship of FIG. 1. FIG.
3 is a side cross-sectional view enlarging an NGH cargo hold portion.
4 is a front sectional view in which an NGH cargo hold portion is enlarged.

EMBODIMENT OF THE INVENTION Hereinafter, with reference to drawings, the regasifiable NGH (natural gas hydrate) transport ship of embodiment which concerns on this invention, and the NGH regasification method in an NGH transport ship are demonstrated.

As shown in FIG. 1 and FIG. 2, the regasification NGH transport ship 1 of embodiment which concerns on this invention is an inboard space enclosed by the ship bottom 2, the ship side shell plate 3, and the upper deck 4. As shown in FIG. The engine room 5 is installed in the rear part of the engine, and the propeller 6 driven by the engine (not shown) installed in this engine room 5 is installed in the stern. A key 7 is provided behind the propeller 6 of the stern, and a residence 8 having a bridge is provided above the engine room 5. As shown in FIG. 1 and FIG. 2, in front of the engine room 5 of the inboard space, the NGH cargo hold 10 which accommodates NGH pellets is provided in multiple numbers. In Fig. 1 and Fig. 2, ten NGH cargo holds 10 are provided in five rows (No. 1 to No. 5) in the right and left directions in each of two rows in the horizontal direction (line width direction) and in the front and rear directions (captain direction). have.

As shown in FIGS. 1-4, the gas discharge pipe 11 which leads | induces the decomposition gas of NGH pellets is provided in the upper part of this NGH cargo hold 10, and the gas discharge pipe 11 which this gas discharge pipe 11 is connected to is provided. The main pipe 12 for gas is provided, and this gas discharge main pipe 12 is provided so that it can be connected to the land landing pipe of a land side via a gas compressor (not shown). Therefore, at the time of unloading and discharging, the natural gas decomposed in the NGH cargo hold 10 is pumped by the gas compressor via the gas discharge pipe 11 and the main gas discharge main pipe 12 so as to be able to land in the land landing pipe. Configure.

In addition, a circulating water sprinkler 13 for sprinkling circulating water serving as a heat source for decomposing NGH pellets is provided on the upper portion of each NGH cargo hold 10. The circulating water sprinkler 13 is connected to the upper circulating water pipe 15 with the circulating water supply pipe 14 interposed therebetween.

In the present invention, the circulating water drop pipe 16 is provided inside the NGH cargo hold 10. The circulating water drop pipe 16 is formed with an opening 16a through which NGH pellets larger than the size of a particle set in advance does not penetrate, and the circulating water in the NGH cargo hold 10 is opened from the opening 16a to an NGH cargo hold ( It is comprised so that it may lead to the circulation water piping 18 of the lower part via the drain piping 17 arrange | positioned below the bottom part 10a of 10).

In addition, the circulating water dropping pipe is formed so that the circulating water in the upper portion of the NGH pellet layer can be introduced into the circulating water dropping pipe 16 even when the NGH pellet layer is degraded due to decomposition of the NGH pellets in the NGH cargo hold. 16a is set to the several position of the up-down direction of the circulation water dripping pipe 16. FIG.

In addition, a compartment is provided between the engine room 5 and the NGH cargo hold 10 in front of the engine room 5 to form a pump room 20, and the pump room 20 serves as a heat source for decomposing NGH pellets. A heat exchanger 22 for supplying heat to the circulating water and a circulation pump 21 for circulating the circulating water between the NGH cargo hold 10 and the heat exchanger 22 are connected to each other by a pipe. In addition, if the driving source provided in the engine room 5 is configured to drive the circulation pump 21, the driving source is driven by driving the circulation pump 21 in the engine room 5 which is explosion-proof. It is possible to set it to non-explosion proof specification.

The lower circulation water pipe 18 is connected to the circulation pump 21, and the upper circulation water pipe 15 is connected to the heat exchanger 22. Moreover, the structure which connects the lower circulation water piping 18 to the heat exchanger 22, and the upper circulation water piping 15 to the circulation pump 21 may be sufficient. In addition, the heat exchanger 22 may be provided in the gas engine room installed on the ship instead of the same compartment as the circulation pump.

Next, the NGH regasification method performed by the regasification NGH transport ship 1 etc. of this structure is demonstrated. The NGH regasification method in this NGH transport ship is the NGH regasification method performed when gasifying NGH pellets and landing in gas state, and operates the circulation pump 21, and the NGH cargo hold which accommodates NGH pellets ( 10) From the upper part, the circulating water at the seawater temperature, which is a heat source for decomposing NGH pellets, is sprinkled from the circulating water sprinkler 13 at the tip of the circulating water supply pipe 14, and decomposed by the circulating water heat. The generated NGH cracked gas is derived from the gas discharge pipe 11 installed on the upper portion of the NGH cargo hold 10. In addition, it is possible to control the amount of gasification in the NGH cargo hold 10 in accordance with the temperature and the input amount of the circulating water. Further, since the decomposed water generated by NGH decomposition can be used as the circulating water, the first circulating water may be a small amount.

At the same time, the circulating water in the NGH cargo hold 10 is introduced into the circulating water dropping pipe 16 from the opening 16a and into the drain pipe 17 disposed below the bottom 10a of the NGH cargo hold 10. The circulated water derived from the drain pipe 17 is sent to the lower circulating water pipe 18. In this case, when a large particle of NGH pellets intrudes from the drain pipe 17 into the lower circulation water pipe 18, the NGH pellets are gasified, and the gasified natural gas is returned to the circulation pump 21. Since the performance of the circulation pump 21 is significantly reduced, in order to prevent this, it is preferable not to pass only the NGH pellets of small particles that seem to be completely gasified in the circulation water dropping tube 16 to pass through the opening 16a. And it is preferable to form the opening part 16a by the structure which NGH pellet larger than the magnitude | size of a predetermined particle | grains does not penetrate.

The circulating water sent to the lower circulation water pipe 18 is circulated to the heat exchanger 22 by the circulation pump 21, and the heat exchanger 22 exchanges heat with seawater. The circulating water whose temperature has risen by this heat exchanger is again sprinkled in the NGH cargo hold 10 by the circulating water sprinkler 13 at the tip of the circulating water supply pipe 14 via the upper circulating water pipe 15. do.

By repeating this, it is possible to transfer heat energy which seawater has to NGH pellets in the NGH cargo hold 10 with circulating water therebetween, and to decompose the NGH pellets. When all the NGH pellets in the NGH cargo hold 10 have been completely disassembled, the circulation pump 21 is stopped to finish discharging and unloading. In addition, although the circulation pump 21 is used for circulation of circulating water, it is necessary to provide a separate pump for supplying seawater to the heat exchanger 22, and to continuously transfer the thermal energy of the seawater to the circulating water during regasification. have.

In addition, the gas gasified in the NGH transport ship 1 is compressed and supplied by a gas compressor in accordance with the demand value on the demand side, but has a pressure-resistant structure in the NGH cargo hold 10, so that the gasification pressure in the NGH cargo hold 10 Configure to raise As a result, by raising the gasification pressure in the NGH cargo hold 10 in the NGH transport ship 1 by atmospheric pressure, the pressure in the gas compressor can be reduced and the size of the gas compressor can be made smaller than in the gasification near the atmospheric pressure. In addition, it is possible to reduce the power.

=3.68)에 상당하는 수치이고, 이 압력까지 NGH 화물창(10)내의 가스화 압력을 승압하는 것에 의해, 가스압축기의 동력을 약 1/3로 하는 것이 가능하다.In addition, since the gas pressure required on land is about 5 MPa (gauge pressure), when gasified at atmospheric pressure, it is necessary to rise by the gas compressor from atmospheric pressure to about 5 MPa (gauge pressure). When 10) is configured to gasify at 0.4 MPa (gauge pressure), the first stage (when the elevated pressure of about 50 is increased in three stages in the pressure ratio (

= 3.68), and by increasing the gasification pressure in the NGH cargo hold 10 to this pressure, it is possible to make the gas compressor power about 1/3.

According to the regasificationable NGH transporter 1 and the NGH regasification method in the NGH transporter, the circulating water, which is a heat source for decomposing NGH, freezes in the NGH pellet layer and hardly penetrates into the NGH pellet layer, Although it may stay in the upper part of the NGH pellet layer, even in this case, the circulated water which has stayed is passed through the vertical circulating water drop pipe 16 installed inside the NGH cargo hold 10, and the bottom of the NGH cargo hold 10 is provided. It is possible to lead to the external circulating water pipe 18 of the NGH cargo hold 10 from the drain pipe 17 connected to the lower portion of the circulating water drop pipe 16 by descending below 10a.

This ensures a drainage path of the circulating water by the circulating water dropping tube 16, thereby preventing the passage of the flow path due to freezing of the circulating water at the upper portion of the NGH pellet layer and a poor drainage. Since the circulating water sprinkled from the upper portion of the NGH cargo hold 10 through the pipe 16 can be drained to the drain pipe 17 below the bottom 10a of the NGH cargo hold 10, It is possible to prevent the circulating water from overflowing.

As a result, it is possible to efficiently regasify the NGH pellets mounted on the NGH cargo hold 10 of the regasifiable NGH transport ship 1 using the circulating water.

That is, with a simple configuration, by passing through the heat exchanger, the circulating water serving as a low-temperature heat source of seawater temperature obtained by heat exchange with seawater is sprinkled in the upper portion of the NGH cargo hold 10, and the sprinkled circulating water is converted into an NGH cargo hold ( 10) led to the bottom 10a of the NGH cargo hold 10 through the circulating water descent pipe 16 installed in the vertical direction, and to the outside of the NGH cargo hold 10 than the bottom 10a of the NGH cargo hold 10. By leading to the installed heat exchanger 22, the NGH pellets can be stabilized in a simple configuration and efficiently regasified.

Industrial availability

According to the regasificationable NGH (natural gas hydrate) transporter of the present invention and the NGH regasification method in the NGH transporter, it is possible to stabilize and efficiently regasify the NGH pellets in the NGH cargo hold of the NGH transporter with a simple configuration. Therefore, it is possible to use for an NGH transport ship. Moreover, even in the NGH transport ship provided with the mechanical unloading apparatus which lands as NGH pellets without regasification, it can be used for emergency gasification when this mechanical unloading apparatus and the land side unloading apparatus fail.

1 Regasifiable NGH Transport
5 engine room
10 NGH cargo hold
10a bottom
11 Gas Exhaust Pipe
12 Main building for gas discharge
13 circulating water sprinkler
14 Circulating water supply pipe
15 Circulating water pipe at the top
16 circulating water drop pipe
16a opening
17 Drainage Pipe
18 Lower water piping
20 pump rooms
21 Circulation pumps
22 heat exchanger

Claims (6)

An NGH transport vessel for accommodating NGH pellets, a heat exchanger for supplying heat to circulating water as a heat source for decomposing NGH pellets, a circulating water pipe for circulating the circulating water between the NGH cargo hold and the heat exchanger, and a circulation pump At the same time,
In the upper part of the NGH cargo hold, a gas discharge pipe for drawing the decomposition gas of the NGH pellets, and a circulating water sprinkler for spraying the circulating water,
In addition, a circulating water dropping pipe is installed inside the NGH cargo hold to lead the circulating water in the NGH cargo hold to the circulating water pipe via a drain pipe disposed below the bottom of the NGH cargo hold at an opening. Regasifying NGH Transporter. The method according to claim 1,
The heat exchanger and the circulation pump are installed in a compartment provided between the engine room and the NGH cargo hold in front of the engine room, and at a drive source provided in a non-hazardous compartment of the engine room or the motor room adjacent to the compartment. Recirculating NGH transport ship characterized in that for driving the circulation pump. The method according to claim 1 or 2,
A regasifiable NGH transport ship using decomposed water generated by regasification of NGH as circulating water. The method according to any one of claims 1 to 3,
A regasification NGH transporter characterized by regasification of NGH at a landing site and returning the decomposed water generated by regasification to an appropriate site, so that no seawater ballast is required. The method according to any one of claims 1 to 4,
Re-gasification NGH transport ship having a pressure-resistant structure in the NGH cargo hold, raising the gasification pressure in the NGH cargo hold. At the upper part of the NGH cargo hold containing NGH pellets, the circulating water, which is a heat source for decomposing NGH pellets, is sprinkled,
The NGH decomposition gas generated by decomposition by the heat of the circulating water is led to the discharge pipe installed at the upper part of the NGH cargo hold, and
Circulating water in the NGH cargo hold is introduced into the circulating water dropping pipe at the opening, and is led to a drain pipe disposed below the bottom of the NGH cargo hold,
The circulating water derived from the drain pipe is circulated to the heat exchanger by the circulating water pipe and the circulating pump, and the heat exchanger exchanges heat between the circulating water and the seawater to raise the temperature of the circulating water, and again, the NGH. NGH regasification method in the NGH transport ship, characterized in that the water in the upper portion of the cargo hold.

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