JP2002120792A - Device and method for transporting natural gas composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a ship mounted type, motor truck mounted type, or standard type transportation device for compressed natural gas used for container transportation, which is designed to operate at the environment temperature or slightly lower than that. SOLUTION: Use of complex compression containers provides crucial advantages in comparison with conventional compressed natural gas transportation for which a steel or steel-lining compression container is provided and used. The destruction characteristic of the complex compression containers is excessively superior to that of the conventional steel or steel-lining compression container. Substantial decrease in weight realized in the complex compression containers, which provide uniform pressure, clearly solves weight-related problems accompanying the idea of use of the steel or steel-lining compression container. The corrosion resistant characteristic of complex compression containers enables transportation of raw compressed natural gas or compressed liquefied natural gas having high corrosion possibilities. Use of complex compression containers provided with a corrosion resistant liner eliminates necessity to process gas or liquid at or near the supply source thereof.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to gas transport,
More particularly, the present invention relates to an apparatus and method for transporting a natural gas composition.

[0002]

2. Description of the Related Art At present, natural gas or natural gas liquid (NG)
L) There are three basic means of transport.

[0003] The first usually most practical and feasible means of transporting natural gas and NGLs is the pipeline. Topographic obstacles are generally the only reason a pipeline is not practical or feasible.

[0004] The second most common form of natural gas transport is liquefied natural gas (LNG). Unfortunately, LNG involves associated high capital expenditures and requires a cold storage liquefaction plant near the source and a regasification plant at the point of discharge. Liquefaction plants are generally large-scale and are therefore neither practical nor viable for offshore gas production.

[0005] A third form of natural gas and liquid transport is compressed natural gas (CNG) and compressed natural gas liquids. Unfortunately, the notions of traditional CNG are:
It simply proposes the use of steel or steel lined compression vessels. These proposed ideas are overweight,
It has inherent problems such as significant safety concerns due to corrosion and severe fracture properties. In the event of a failure of one compression vessel, there is the possibility that other surrounding vessels will fail. For this reason, the certification body never approved the CNG idea of using steel compression vessels. A representative example of the prior art in this regard is September 8, 1998.
No. 5,803,005 issued to Stenning et al.

[0006] In the distant past, several CNG shipping pilot schemes have been attempted. Unfortunately, it has been found that the weight of the steel compression vessel required to implement the potential scheme is too heavy for vessel operation. Excessive weight has caused stability problems and draft concerns. Taking care of such a heavy ship would not be possible in a dry dock anywhere in the world.

[0007] To obtain a practical and feasible means of transporting CNG, a safe and relatively lightweight compression vessel is required. In addition, a compression vessel that resists corrosion will enable the transport of raw and natural gas and NGLs.

[0008] The safety is enhanced by several orders of magnitude due to the fracture characteristics of the composite compression vessel. The fracture characteristics of composite compression vessels are opposite to those of steel or steel lined compression vessels. The method of constructing the composite compression vessel eliminates the spread of cracks caused by projectiles penetrating the walls of the compression vessel. This eliminates the severe fracture and debris potential associated with steel compression vessels. This also eliminates the potential for sudden failure due to the domino effect. Composite compression vessels also have a wider temperature range without loss of strength than conventional steel or steel lined compression vessels.

The use of a composite compression vessel overcomes weight-related problems with the use of conventional steel or steel lined compression vessels. Comparable composite compression vessels are 70% lighter than conventional steel compression vessels.

[0010] Unlike steel or steel lined compression vessels, composite compression vessels do not corrode. The proposed composite compression vessel is
Has a non-metallic liner. Thus, the use of a non-corrosive composite compression vessel allows for the storage of raw and natural gas or NGL.

In view of the earlier proposals, there is a need for an improved apparatus for transporting natural gas or natural gas liquids as discussed herein. The present invention satisfies this need.

One object of the present invention is to provide an apparatus and method for transporting compressed natural gas (CNG) and natural gas liquids (NGL) that is much improved over the prior art for transport by ship, truck or standard vessel. To provide.

[0013] The present invention comprises an NGL transport device in CNG designed to operate at ambient temperature. This CNG transport system is designed for shipping where composite compression vessels are used to overcome safety limitations, weight limitations and corrosion issues associated with the use of steel or steel-lined compression vessels proposed in previous CNG ideas. Shaped, truck mounted and standard type devices.

An object of one embodiment of the present invention is to provide a ship;
A plurality of composite compression vessels for containing CNG and / or NGL; connecting means for loading and unloading of the compression vessels;
On-board equipment to assist in loading and unloading of the compression vessel; and coupling means for interconnecting the vessels, wherein the vessel transfers compressed gas and liquid from the vessel to another vessel of the user's choice. Raw and / or raw CNG, characterized in that the weight distribution in the ship can be adjusted by means of
An object of the present invention is to provide a lightweight ship-mounted device for transporting NGLs.

[0015] In this ship-mounted CNG transport device, the composite compression containers are oriented vertically and are arranged in banks. The cells of each bank are placed in a removable frame for maintenance. A module is made up of two or more banks of cells. Several modules can be present in each compartment of the ship.

All cells of a bank are connected at the top to the gas manifold and at the bottom to the liquid manifold. The manifolds of each bank in the module are then connected to the upper gas module manifold and the lower liquid module manifold, respectively. Each module manifold is then connected to the main gas and liquid pipes of the vessel via respective isolation and control valves.

[0017] Transporting gas and liquid together in a number of compression vessels can result in an undesirable distribution of weight. Thus, a device is required for transferring liquid under pressure from some or all of the composite compression vessels to the designated compression vessel. The ship-mounted CNG transport system incorporates a ballast control unit that integrates a bank and a module to separate free NGLs. Free liquid sinks to the bottom of the cell by orienting the composite compression vessel in the longitudinal direction.
These free liquids are then transferred to one or more designated banks of cells using a slight differential pressure between the gas manifold and the liquid manifold. By controlling the distribution of the liquid, the desired weight distribution of the cargo is obtained and a stable and safe voyage takes place.

Upon reaching the discharge terminal, the gas and liquid can be unloaded separately but simultaneously to minimize delivery time. Refrigeration and insulation can be used to increase capacity and efficiency. Compressors, to increase loading and unloading efficiency
Onboard equipment such as pumps and slag catchers can be used. To maintain consolidated production, several shuttle tankers may be required.

[0019] The structure of the composite compression container varies depending on the companies that manufacture it. A suitable known mold is made by winding adhesive impregnated carbon fibers in a helical path around a high density polyethene (HDPE) liner. The ends of the compression vessel will have integral stainless steel bosses for welding to external piping.

[0020]

Having thus described the present invention, reference will now be made to the accompanying drawings which illustrate a preferred embodiment. Like reference numerals in the figures refer to like elements.

Referring to FIGS. 1-6, the preferred embodiment provides a composite compression vessel to provide a safe, lightweight, ballast controlled and anti-corrosion storage and transport device designed to operate at ambient temperatures. This is a natural gas transport device mounted on a ship.

As an example, the means of transport consists of a shuttle tanker 10 divided into two sides 12 and 14 each having an equal number of compartments. Each compartment can have one or more modules 16. Within each module, many rows of composite compression vessel cells 18 will be housed. The cells 19 in each row are arranged in a row with two or more compression vessels 18 connected in a row in order to make efficient use of the available height in the ship compartment. The cells 19 in each row are supported in a metal frame 20 fixed in the compartment. The frame 20 is configured to be attached or detached without obstructing other frames in the compartment. The frames 20 are arranged offset from each other from the stern side to the bow side.

Each row of cells 19 is provided with an upper gas manifold 11 that connects the tops of the compression vessels 18 in each row.
A lower liquid manifold 13 that separately connects the bottoms of the compression chambers 18 in each row is provided. Control valves 26, 28 are provided at the end of each manifold. Each control valve 26, 28 is connected to a liquid manifold 32 and a gas manifold 24 of each module that connect one or more rows to form a module 16. Each module 16 then has its own isolation valve 32 and control valve
Through 34, it is connected to a liquid main pipe 37 and a high pressure filling and discharging gas main pipe 36 of the ship 10. The upper gas module manifold 24 of each module 16 also has a similar isolation valve 32
And a control valve 34 connected to a low-pressure gas mother pipe 38.

[0024] To aid ballast control, free liquid can be directed or transferred to a designated row of cells. Filled gas is placed on the deck of vessel 10 to direct free liquid to designated cells.
Passed through the above slag catcher. Free liquid is
It is continuously removed from the slag catcher 15 and directed through the liquid mother tube 37 to the designated cell.

To transfer free liquid from a filled or partially filled module to designated cells within the module,
The module is first isolated from the main bus by closing the respective isolation valve. The pressure in the designated row of cells then reduces the isolation and control valves on the gas manifold 11 and gas module manifold 24 to the low pressure gas manifold.
Depressurized by partially opening to 38. Due to the differential pressure,
Free liquid travels through the liquid module manifold 22 to the designated row of cells. Once the transfer is complete, all isolation and control valves are closed. The level of each row of cells will be monitored by a remote command (not shown). Opening and closing of all valves will again be by remote control (not shown).

For more overall ballast control, the liquid
It can be transferred from module to module by a similar differential pressure method using the main mother tube. Crossing line 33 is
Can be used to transfer liquid from one side to the other.

During filling, the module will first be compressed to the supply pressure of the source. If the design pressure is not reached using the supply pressure, the on-board compressor 21 can be used to increase the pressure to the design pressure. Load compression equipment can also be used to facilitate unloading. Liquid pump 23 can also be used for filling, moving and discharging liquid.

When the discharge position is reached, the liquid can be discharged separately, but together with the gas, since the liquid tube 37 is independent of the gas discharge process.

[0029] If feasible and deemed necessary, refrigeration and insulation can be used to increase the efficiency and capacity of the storage device.

Each row of cells has a flare boo
There will be an emergency release device connected to m).
For additional safety, the compartments of the shuttle tanker can be filled with inert gas and the oxygenated air can be exchanged.

It would be advantageous if the shuttle tanker used natural gas or liquid natural gas as power.

[0032] In order to maintain linked production, several shuttle tankers will be required. The number and size of these shuttle tankers, as well as the number of compression vessels and pressure vessels, will be determined by optimal considerations of criteria such as production requirements, unloading facilities (speed and volume capacity) and cost.

Transportation of natural gas and liquid natural gas by truck and modular container will be similar to that of marine equipment.

While the embodiments of the present invention have been described above, it is not intended that the invention be limited to many embodiments without departing from the spirit, nature and scope of the claimed and described invention. Variations will be apparent to those skilled in the art.

[Brief description of the drawings]

FIG. 1 is a plan view of a shuttle tanker showing a compartment and a bank of a cabin.

FIG. 2 is an elevation view of a shuttle tanker.

FIG. 3 is a schematic diagram of a typical bank in a cabin.

FIG. 4 is a schematic diagram of a typical compartment having multiple modules.

FIG. 5 is an elevation view of a representative frame including one bank in the cabin.

FIG. 6 is a schematic diagram of the entire configuration of a shuttle tanker module, equipment, and piping.

[Explanation of symbols]

 10 Shuttle tanker (ship) 11 Upper gas manifold 15 Slag catcher 16 Module 18 Compression container 19 cell

Claims (12)

[Claims] Claims 1. A lightweight, anti-corrosion marine onboard apparatus for transporting raw raw compressed natural gas or compressed liquid natural gas, comprising: a ship; raw raw compressed natural gas; Composed of a plurality of composite compression vessels for liquid natural gas and connecting means for connecting the vessels, the vessels being integrated to transfer the compressed gas and liquid from the vessel to another vessel of the user's choice. A transport device mounted on a ship, wherein the transport device is connected and a weight distribution in the ship is adjusted. 2. The composite compression vessel is vertically arranged in groups coaxial with the length of the vessel, each group connecting a bottom of each vessel and a lower liquid manifold means terminating in a liquid isolation valve. And a top gas manifold connecting the tops of each vessel and terminating with a gas isolation valve.
The transport device mounted on a ship according to the above. 3. At least two groups of vessels; a liquid sub-manifold (22) connecting all liquid manifolds at each group of isolation valves in the module and terminating at the module isolation valves; Connect all gas manifolds at each group of isolation valves and sub-manifolds for gases ending with module isolation valves (24)
3. The transport device mounted on a ship according to claim 2, comprising: 4. A loading and unloading host tube, whereby gas loading and unloading is achieved by a host tube connected to each module at a gas isolation valve for gas loading and unloading. Claims characterized in that
4. The transport device mounted on a ship according to 3. 5. Having a liquid mother pipe, whereby liquid loading and unloading is achieved by a mother pipe connected to each module at a liquid isolation valve for liquid loading, unloading or transport. 4. The transport device mounted on a ship according to claim 3, wherein: 6. A gas supply and unloading is achieved by means of a mains pipe connected to each module at a gas isolation valve for loading and unloading gas, having a low-pressure host pipe. 4. The transport device mounted on a ship according to claim 3, wherein the transport device is mounted. 7. The transport device mounted on a ship according to claim 3, wherein the ship is divided into two rows. 8. At least one slag catcher for removing liquid in a direction from a loading stream to a designated cell of a compression vessel; and at a pressure required for loading, unloading or transferring natural gas. Further comprising at least one compressor for compressing natural gas; and at least one liquid pump for pumping the liquid to the required pressure for loading, unloading or transferring liquid. The transport device mounted on a ship according to claim 1. 9. Providing a plurality of composite compression vessels for receiving gas or liquid into the vessel; providing coupling means for interconnecting the vessels; introducing gas or liquid into the compression vessel; Selecting a compression vessel that receives the gas or liquid to adjust the weight distribution of the compression vessel in the vessel for transporting the gas or liquid; A method for loading, unloading and transferring natural gas and compressed natural gas liquid. 10. The method according to claim 9, characterized in that the stored natural gas can be unloaded separately and simultaneously with the natural gas liquid by means of a gas pipeline and a compressor. 11. The method according to claim 9, wherein the stored liquid is unloaded separately and simultaneously with the natural gas by a liquid main pipe and a liquid pump. 12. The method of claim 8, further comprising moving the liquid or gas from one bank of compression vessels to another by differential pressure.