阅读说明：本技术 浮体式结构物 (Floating structure ) 是由 岸本直彦 角田和亮 秋山治之 円谷晃司 于 2018-10-11 设计创作，主要内容包括：本发明提供一种浮体式结构物,一方面确保贮藏液化天然气的LNG槽罐的配置空间,一方面配置有天然气处理设备。浮体式结构物包括：槽罐,从现存的LNG运输船或现存的浮体式结构物移装,在船身部的长度方向上连续地配置；以及天然气处理设备,在所述船身部的宽度方向上,配置于所述槽罐的两侧之中的至少一侧,并且,所述天然气处理设备配置于所述船身部的宽度方向内侧。(The invention provides a floating structure, which ensures the arrangement space of an LNG tank for storing liquefied natural gas and arranges natural gas processing equipment. The floating structure includes: a tank which is installed from an existing LNG carrier or an existing floating structure and is continuously arranged in the longitudinal direction of the hull; and a natural gas treatment facility disposed on at least one of both sides of the tank in a width direction of the hull, and the natural gas treatment facility is disposed on an inner side of the hull in the width direction.)

1. A floating structure comprising:

a tank which is installed from an existing liquefied natural gas carrier or an existing floating structure and is continuously arranged in the longitudinal direction of the hull; and

a natural gas processing facility disposed on at least one of both sides of the tank in a width direction of the hull portion, and configured to process natural gas

The natural gas processing facility is disposed on the inner side in the width direction of the hull portion.

2. The floating structure according to claim 1, wherein the natural gas processing apparatus is disposed at both sides of the tank.

3. The floating structure according to claim 1 or 2, wherein the natural gas processing facility is disposed along a starboard side of the hull portion and a port side of the hull portion.

4. The floating structure according to any one of claims 1 to 3, wherein the natural gas processing apparatus comprises: the pretreatment equipment is used for pretreating the natural gas; and a liquefaction facility for liquefying the natural gas,

the pretreatment equipment is arranged at the end part of the hull part in the length direction,

the liquefaction facility is disposed on the inner side in the width direction of the hull portion.

5. The floating structure according to any one of claims 1 to 4, wherein the natural gas processing apparatus comprises: the pretreatment equipment is used for pretreating the natural gas; and a liquefaction facility for liquefying the natural gas,

the liquefaction facility is disposed inside the hull portion in the width direction and provided with two series,

one series of the liquefaction facilities is disposed on a starboard side of the hull portion, and the other series of the liquefaction facilities is disposed on a port side of the hull portion.

6. The floating structure according to claim 4 or 5, wherein the liquefaction facility and the tank are connected by a pipe for transporting liquefied natural gas liquefied by the liquefaction facility to the tank.

7. The floating structure according to any one of claims 1 to 6, wherein six or more tanks are continuously arranged in a longitudinal direction of the hull portion.

8. The floating structure according to any one of claims 1 to 7, wherein the tank is a spherical tank.

Technical Field

The present invention relates to a floating structure, and more particularly to a floating structure in which a tank is installed on an existing Liquefied Natural Gas (LNG) carrier or floating structure.

Background

It has previously been known that LNG tanks which are non-corrosive in the loaded LNG do not tend to increase the ageing. In view of the properties of such LNG tanks, a technique of building a new floating structure by transferring and installing an aged LNG tank of an LNG carrier has been proposed (for example, see patent document 1). According to the above-described technology, the LNG tank which takes a long time for manufacturing is recycled as a tank for storing liquefied natural gas, and the construction process of a newly constructed floating structure can be significantly shortened.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open No. 2012-86768

Disclosure of Invention

Problems to be solved by the invention

However, in the above technique, a natural gas processing apparatus may be further provided in the novel floating structure. In this case, as shown in fig. 2(a) and 2(b), it is conceivable to dispose the natural gas processing facility 108 near the bow side. However, if the LNG tank 106 is arranged in this manner, the arrangement space of the LNG tank 106 becomes narrow, which may affect the number of LNG tanks 106.

Further, when the LNG tank 106 is disposed at the center of the hull 104, it is difficult to secure a space for disposing the natural gas processing facility 108 on the side. Therefore, it is also conceivable to add an extension in the width direction of the board side and to dispose the natural gas processing facility 108 in the extension. However, in this case, a new problem arises in that the size of the floating structure 102 increases.

The invention aims to provide an elongated floating structure, which ensures the arrangement space of a tank and arranges natural gas processing equipment.

Means for solving the problems

The floating structure of the present invention is a floating structure including:

a tank which is installed from an existing LNG carrier or an existing floating structure and is continuously arranged in the longitudinal direction of the hull; and

a natural gas treatment facility disposed on at least one of both sides (side) of the tank in a width direction of the hull portion, and configured to treat natural gas

The natural gas processing facility is disposed on the inner side in the width direction of the hull portion.

In the floating structure of the present invention,

the natural gas processing equipment is arranged on two sides of the tank.

In the floating structure of the present invention,

the natural gas processing facility is disposed along a starboard side of the hull portion and a port side of the hull portion.

In the floating structure of the present invention,

the natural gas processing plant comprises: the pretreatment equipment is used for pretreating the natural gas; and a liquefaction facility for liquefying the natural gas,

the pretreatment equipment is arranged at the end part of the hull part in the length direction,

the liquefaction facility is disposed on the inner side in the width direction of the hull portion.

In the floating structure of the present invention,

the natural gas processing plant comprises: the pretreatment equipment is used for pretreating the natural gas; and a liquefaction facility for liquefying the natural gas,

the liquefaction facility is disposed inside the hull portion in the width direction, and two series are provided,

one series of the liquefaction facilities is disposed on a starboard side of the hull portion, and the other series of the liquefaction facilities is disposed on a port side of the hull portion.

In the floating structure of the present invention,

the liquefaction facility and the tank are connected by a pipe for transporting the liquefied natural gas liquefied by the liquefaction facility to the tank.

In the floating structure of the present invention,

six or more tanks are continuously arranged in the longitudinal direction of the hull.

In the floating structure of the present invention,

the tank is a spherical tank.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the present invention, it is possible to provide an elongated floating structure in which a natural gas treatment facility is disposed while securing a space for disposing an LNG tank for storing liquefied natural gas.

Drawings

Fig. 1 is a schematic view of a floating structure according to an embodiment.

Fig. 2 is a schematic view of a conventional floating structure.

Detailed Description

Hereinafter, a floating structure according to an embodiment of the present invention will be described with reference to the drawings. Fig. 1(a) is a schematic view of the floating structure 2 of the embodiment as viewed from above, and fig. 1(b) is a schematic view of the floating structure 2 as viewed from the side (starboard side). As shown in fig. 1(a) and (b), the floating structure 2 is an offshore structure mainly composed of a hull portion 4. In the floating structure 2 of the embodiment, six tanks 6 are continuously arranged in a line in the central longitudinal direction of the hull 4. Between the adjacent tanks 6, a transverse partition wall (not shown) spanning between the two sides is disposed as appropriate. Further, the floating structure 2 is provided with a natural gas treatment facility 8, a residential area 10, a residential area 12, and a power plant 14. The "hull portion" in the present embodiment refers to a structure having an outer edge defined as one structure at the time of construction, and the concept does not include a structure (hereinafter, also referred to as an extension portion) to be additionally joined to expand the structure after construction.

The floating structure 2 can be used as an offshore plant (offset plant). As such facilities, Floating Production Storage and Offloading (FPSO) facilities that perform Production, Storage, and Offloading of oil, natural gas, and the like, Floating Storage and Offloading (FSO) facilities that perform Storage and Offloading only without Production facilities, Floating Storage Units (FSU) that perform Storage only, and the like are known. As one of FPSOs, Floating Liquefied Natural Gas (FLNG) plants and the like are known, which are dedicated to the production, storage, and offloading of Liquefied Natural Gas (LNG). In the embodiment of the present invention, a case where the floating structure 2 is FLNG will be described as an example. Further, the floating structure 2 does not have a self-propelling function, and is towed by a power boat when moving.

The hull portion 4 is a structure having a length direction and a width direction and being long in one direction. The hull portion 4 may be referred to as a hull (hull), and the hull portion may be of a double structure and may be referred to as a double hull (double hull). In the floating structure 2 of the embodiment, the hull 4 is a newly constructed member. The total length of the hull 4 in the present embodiment is assumed to be 350 to 450m, but the total length of the hull 4 may be longer or shorter than this.

The tank 6 is a spherical tank made of an aluminum alloy having a diameter of about 25 to 60m and stores liquefied natural gas cooled at-162 ℃. Specifically, the liquefaction facility 8b described later and the tank 6 are connected by a pipe not shown. The liquefied natural gas liquefied by the liquefaction facility 8b is transferred to the tank 6 through the pipe and stored in the tank 6. Such spherical tanks 6 are known as Moss spherical tanks. The upper part of the tank 6 protrudes from the hull 4 and is covered with a steel tank cover (tank cover), not shown. The lower part of the tank 6 is housed inside the hull 4. These tanks 6 are transferred from an existing LNG carrier, and are arranged continuously with their centers aligned in a line in the longitudinal direction of the hull 4. Further, since the moss ball tank of the existing floating structure is not aged more and can be used sufficiently, the strong tank can be recycled at low cost.

The natural gas processing facility 8 includes a pretreatment facility 8a, a heavy component removal facility (not shown), and a liquefaction facility 8 b. The pretreatment facility 8a is a facility for performing a step preceding the liquefaction of the raw natural gas supplied from the wellhead, and is disposed on the bow side of the hull portion 4. In the pretreatment facility 8a, processes up to a separation step of separating condensate (condensate) contained in the raw material natural gas, an acid gas removal step of removing acid gas, a mercury removal step of removing mercury, and a dehydration step of performing dehydration treatment are performed.

Here, in the separation step, the separated condensate is stored in a condensate tank, not shown. In the acid gas removal step, an amine (amine) is brought into counter-current contact with the raw material natural gas in an absorption tower (not shown) to absorb the amine to remove the environmental pollutants such as carbon dioxide and hydrogen sulfide.

The mercury removal step is a step of removing mercury from the raw natural gas when the raw natural gas contains a trace amount of mercury vapor. Mercury corrodes aluminum alloys used as low temperature components and must be removed. In the dehydration step, moisture is removed from the raw material natural gas from which the impurities have been removed by the adsorbent. The dehydration is performed for the purpose of preventing the freezing of the piping due to the formation of ice in the subsequent liquefaction step.

Further, since the composition of the raw natural gas differs from well head to well head, the amount of the removal target substance to be removed in the pretreatment facility 8a contained in the raw natural gas also differs from well head to well head. That is, since the type and size of the equipment disposed in the pretreatment facility 8a are designed according to the properties of the raw natural gas at the well, there is a possibility that the type and size of the equipment may differ depending on which well is treated with the raw natural gas.

For example, when the feed natural gas at the wellhead contains a greater amount of CO than usual₂Or mercury, the capacitance (capacity) of the equipment that performs the acid gas removal step or the mercury removal step increases. Therefore, the pretreatment equipment 8a is preferably disposed in a relatively wide space such as a bow side where the tank 6 is not disposed, so that the layout space can be flexibly designed, for example, enlarged or reduced, depending on the type and size of the equipment. Further, by disposing the pretreatment facility 8a on the bow side, even when a design change occurs due to a change in the composition of the raw natural gas, the design change of the pretreatment facility 8a has little influence on the design of the entire hull portion because the length of the hull portion 4 in the longitudinal direction can be adjusted to cope therewith.

In the heavy component removal apparatus, a heavy component removal process of removing heavy components from the raw natural gas is performed. The heavy component removal equipment is a part for separating the natural gas treated by the pretreatment equipment 8a into fractions of methane, ethane, propane, and the like. In the heavy component removal equipment, in addition to methane, heavy hydrocarbons such as ethane, propane, butane, and the like are separated and recovered. The heavy component removal facility may be disposed adjacent to the pretreatment facility 8a at the bow, or may be disposed on the side of the tank 6 in the width direction of the hull portion 4. Further, some of the devices provided in the heavy component removal facility may be disposed on the bow side, and the other devices may be disposed on the side of the tank 6.

The liquefaction facility 8b is a facility for performing a step of liquefying the raw natural gas, and is disposed on both sides of the tank 6 in the width direction of the hull 4. The liquefaction facility 8b is provided in two series, one series of liquefaction facilities 8b is disposed on the starboard side of the hull portion 4 in the longitudinal direction, and the other series of liquefaction facilities 8b is disposed on the port side of the hull portion 4 in the longitudinal direction. In the present embodiment, two series of liquefaction facilities 8b are provided for one pretreatment facility 8 a. In the present embodiment, the starboard-side liquefaction facility 8b and the port-side liquefaction facility 8b are opposed to each other with the tank 6 interposed therebetween so as to be located at the same position in the longitudinal direction of the hull 4 (overlap in the width direction of the hull 4).

The liquefaction facility 8b is disposed on the inner side of the hull portion 4 in the width direction so as not to be exposed to the hull portion 4. Therefore, it is not necessary to add an extension portion in the width direction to secure an arrangement space on the side, and the hull portion 4 can be designed to be slim. The liquefaction facility 8b is provided with a heat exchanger for liquefying methane separated by a demethanizer (not shown), a refrigerant circuit (coolants circuit) for supplying a refrigerant to the heat exchanger, and the like. In the present embodiment, the two liquefaction plants 8b of the two series are designed such that the respective machines (the heat exchanger and the refrigerant circuit) are of the same size so as to be able to produce the same amount of liquefied natural gas.

In the liquefaction facility 8b, a liquefaction process of liquefying the raw material natural gas is performed. Specifically, the liquefaction facility 8b is a portion that liquefies methane separated by the demethanizer in the heavy component removal unit. In the liquefaction step, the raw natural gas sent to the heat exchanger is heat-exchanged with the low-temperature gas supplied from the refrigerant circuit, and is cooled to-162 ℃ or lower to be liquefied. The liquefied low-temperature raw natural gas is sent to the tank 6 through a pipe and stored in the tank 6.

Here, since the liquefaction facility 8b is a facility for disposing of the raw natural gas processed in the pretreatment facility 8a, the size of the equipment, the installation position of the equipment, and the like can be determined in advance by determining the production amount of the raw natural gas. That is, the liquefaction facility 8b is a facility with few fluctuating elements. Therefore, it is also possible to previously design the liquefaction facility 8b in an elongated shape extending in one direction along the length direction of the hull 4 at an early stage. By performing the above design in advance, as shown in fig. 1, the liquefaction facility 8b can be designed along the starboard and the port of the hull 4 so as to save space on the side of the tank 6.

The living area 10 is an equipment including a crew room, a kitchen, and the like, and the rest area 12 is an area where target equipment and the like at the time of maintenance are temporarily placed. The power plant 14 is a facility including a generator for operating the natural gas processing facility 8. The residential area 10, the parking area 12, and the power plant 14 are all disposed on the stern side.

According to the invention of the present embodiment, it is possible to provide an elongated floating structure in which the liquefaction facility 8b having a small layout variation factor is designed in advance in an elongated shape extending in one direction along the longitudinal direction of the hull 4 and is disposed on both sides of the tank 6, thereby ensuring the disposition space of the tank 6 and disposing the natural gas treatment facility 8.

Further, since the layout of the liquefaction facility 8b is less subject to variation, the liquefaction facility 8b is designed in advance in a slender shape corresponding to the space on the side of the tank 6 in the width direction of the hull portion 4, and thereby the floating structure 2 can be made in which the space on both sides of the tank 6 is effectively utilized and the length of the hull portion 4 in the width direction is suppressed.

Further, by disposing the natural gas treatment facility 8 along the starboard and the port of the hull portion, dead space (dead space) on the hull portion 4 can be effectively utilized. Further, if six or more tanks 6 are arranged in the longitudinal direction of the hull 4, the space for arranging the liquefaction facility 8b is sufficiently secured, and therefore the design of the liquefaction facility 8b can be established in advance. Further, since the arrangement space of the natural gas processing facility 8 does not overlap the arrangement space of the tanks 6, it is not necessary to reduce the number of tanks 6. Further, by disposing the liquefaction equipment 8b on the widthwise inner side of the hull portion 4, it is not necessary to add an extension portion to secure a space for disposing the liquefaction equipment 8b on the board side.

Further, by collectively disposing the pretreatment apparatuses 8a on the bow side and disposing the liquefaction apparatuses 8b on both sides of the tank 6, the length (X) from the tank 6 located on the most bow side to the stern of the hull 4 can be determined in advance, and the length (Y) from the bow to the tank 6 can be changed. Therefore, the design and construction period of the floating structure 2 can be shortened, and the design change of the pretreatment equipment 8a can be flexibly coped with.

Further, by providing two series of liquefaction plants 8b for one pretreatment plant 8a, even if one liquefaction plant 8b stops operating and a state in which natural gas cannot be produced is assumed, the production of natural gas can be continued by the other liquefaction plant 8 b.

Further, by providing two series of liquefaction facilities 8b for one pretreatment facility 8a and disposing the two series of liquefaction facilities 8b with the tank 6 interposed therebetween, it is not necessary to connect the liquefaction facility 8b disposed on the starboard side of the hull portion 4 and the liquefaction facility 8b disposed on the port side of the hull portion 4 with pipes. That is, the liquefaction facility 8b is a facility that performs a process at the final stage of the natural gas treatment facility 8, and liquefied natural gas is discharged as a product to the tank 6. Therefore, since there is no need to connect piping to the right-side liquefaction facility 8b and the left-side liquefaction facility 8b without transferring fluid, there is no need to lay piping in the region where the tank 6 is provided. Therefore, the number of pipes disposed in the natural gas processing facility 8 can be significantly reduced, and the design of the pipes is facilitated.

In the present embodiment, the starboard-side liquefaction facility 8b and the port-side liquefaction facility 8b are opposed to each other with the tank 6 interposed therebetween so as to be located at the same position in the longitudinal direction of the hull 4 (overlap in the width direction of the hull 4). Therefore, the range or the position of the region where the equipment other than the liquefaction equipment 8b is installed is determined in advance, and therefore the layout of the starboard side and the port side becomes easy. Further, since the right-side liquefaction plant 8b and the left-side liquefaction plant 8b are designed to have the same size, the design of one of the plants can be used for the design of the other plant, and the design of the liquefaction plant 8b itself becomes easy.

Further, since the floating structure 2 is constructed by recycling the tank 6 provided in the existing floating structure, the cost and the time required for manufacturing the tank 6 are not required. Therefore, the floating structure 2 can be provided at low cost and with a short delivery time.

In the floating structure 2 of the above embodiment, the case where the natural gas treatment facilities 8 (liquefaction facilities 8b) are disposed on both sides of the tank 6 in the width direction of the hull 4 has been described, but the natural gas treatment facilities 8 may be disposed on either side of the tank 6.

In the floating structure 2 of the above embodiment, the pretreatment equipment 8a may be disposed at an end portion of the hull portion 4 in the longitudinal direction. Therefore, the pretreatment facility 8a may be disposed on the stern side, and the residential area 10, the parking area 12, and the power plant 14 may be disposed on the bow side. The pretreatment equipment 8a may be disposed at the bow and the stern in a divided manner. The power plant 14 may be disposed on one side or both sides of the tank 6 in the width direction of the hull 4. In these cases, too, a wide space that can cope with variations in the type or size of the machine can be secured.

Although not shown in the above embodiment, the pretreatment facility 8a may be disposed on the side of the tank 6 in the width direction of the hull portion 4, and the liquefaction facility 8b may be disposed at least at one of the bow and the stern.

In the floating structure 2 of the above embodiment, the case where six tanks 6 are continuously arranged in the longitudinal direction of the hull 4 is described as an example, but the number of tanks 6 may be seven or more. For example, seven to nine tank tanks 6 may be continuously arranged in the longitudinal direction of the hull 4. Further, it is preferable that six or more tanks 6 are provided, but at least a plurality of tanks may be provided, and the number of tanks 6 may be two to five.

In the above embodiment, the case where two series of liquefaction facilities 8b are provided has been described, but the present invention is not limited to this. The liquefaction facility 8b may be provided in one series or three or more series.

In the above embodiment, the case where two series of liquefaction apparatuses 8b are provided for one pretreatment apparatus 8a has been described, but the present invention is not limited to this. A separate pretreatment apparatus 8a may be provided for each liquefaction apparatus 8 b. For example, the pretreatment facilities 8a may be provided in a single line on the starboard side and the port side so as to correspond to the liquefaction facilities 8b disposed on the starboard side and the port side of the hull portion 4, respectively.

In the above-described embodiment, the case where the respective machines (the heat exchanger and the refrigerant circuit) in the two series of liquefaction plants 8b are designed in the same size has been described, but the machine in one series of liquefaction plants 8b and the machine in the other series of liquefaction plants 8b may be designed in different sizes. At this time, the production amount in one series of liquefaction apparatuses 8b out of the two series of liquefaction apparatuses 8b can be made larger than the production amount in the other series of liquefaction apparatuses 8 b.

In the above embodiment, the case where the right-side liquefaction facility 8b and the left-side liquefaction facility 8b are arranged so as to face each other with the tank 6 interposed therebetween has been described, but the present invention is not limited to this. The starboard-side liquefaction facility 8b and the port-side liquefaction facility 8b may be disposed so as to be different in position in the longitudinal direction of the hull 4 (not to overlap in the width direction of the hull 4). When the liquefaction facility 8b is provided in a plurality of series, all the liquefaction facilities 8b may be disposed on one side of the tank 6 in the width direction of the hull portion 4.

Further, in the above embodiment, the case where the tank 6 is transferred from the existing LNG carrier has been described as an example, but the tank 6 may be transferred from an existing floating structure. In this case, the existing floating structure may be FLNG or the like. That is, the tank 6 can be recycled as long as it is used exclusively as a storage tank for non-corrosive liquefied natural gas.

Further, although the floating structure 2 having no self-propelling function is described as an example in the above-described embodiment, the moving manner of the floating structure 2 is not particularly limited, and the floating structure 2 may have a self-propelling function.

Description of the symbols

2: floating structure

4: body part of ship

6: tank pot

8: natural gas processing plant

8 a: pretreatment equipment

8 b: liquefaction plant

10: residential area

12: resting area

14: power plant

102: floating structure

104: body part of ship

106: LNG tank

108: natural gas processing plant