KR101763701B1

KR101763701B1 - Carbon dioxide operating system

Info

Publication number: KR101763701B1
Application number: KR1020150136558A
Authority: KR
Inventors: 박건영; 고민수; 이종철; 한준희
Original assignee: 삼성중공업 주식회사
Priority date: 2015-09-25
Filing date: 2015-09-25
Publication date: 2017-08-01
Also published as: KR20170037250A

Abstract

Discloses a carbon dioxide operating system. A carbon dioxide operating system according to an embodiment of the present invention includes a storage tank for storing evaporative gas of liquefied carbon dioxide and liquefied carbon dioxide; A first compressor for compressing the evaporated gas supplied from the storage tank; A cooling device for cooling the compressed evaporated gas; A second compressor for receiving and compressing the gas component generated in the cooling device; A heat exchanger for performing heat exchange between the compressed gas component and the heat medium to liquefy the gas component; And a gas-liquid separator for separating the fluid passing through the heat exchanger into a liquid component and a gaseous component.

Description

CARBON DIOXIDE OPERATING SYSTEM [0002]

The present invention relates to a carbon dioxide operating system.

Carbon dioxide accounts for about 70% of the global warming gas, and technologies for reducing atmospheric emissions are being developed by collecting carbon dioxide from steelworks, thermal power plants, etc. and storing it in a seabed storage.

Carbon dioxide can be transported by the ship in a liquefied state. In the storage tank of the ship storing the liquefied carbon dioxide, evaporative gas of liquefied carbon dioxide caused by external heat or the like is present together with liquid carbon dioxide. In order to maintain the carbon dioxide in the liquid phase, it is usually required to maintain at least the triple point (5.16 bar at -56.6 캜) and supercritical (31.1 캜, 74.8 bar).

In order to transport liquefied carbon dioxide with these characteristics to storage, liquefied carbon dioxide is transported to a storage tank during the berth of anchorage, the shipped liquefied carbon dioxide is transferred to the bottom storage, and the characteristics of carbon dioxide Efficient operation should be done.

For example, there is a need to effectively liquefy or utilize the evaporated gas of liquefied carbon dioxide continuously generated in the storage tank from the storage tank until it reaches the seabed storage after using the characteristics of carbon dioxide.

Korean Patent Laid-Open No. 10-2010-0068827 (published on June 24, 2010) filed a concept patent for simultaneous shipment of carbon dioxide and other cargoes, but it does not disclose a specific configuration related to evaporative gas re-liquefaction and efficient carbon dioxide operation have.

Korean Patent Publication No. 10-2010-0068827 (published on June 24, 2010)

The embodiment of the present invention is intended to provide a carbon dioxide operation system that enables effective operation of carbon dioxide operation including liquefied carbon dioxide re-liquefaction.

According to an aspect of the present invention, there is provided a storage tank for storing liquefied carbon dioxide and a vaporized gas of the liquefied carbon dioxide; A first compressor for compressing the evaporated gas supplied from the storage tank; A cooling device for cooling the compressed evaporated gas; A second compressor for receiving and compressing gas components generated in the cooling device; A heat exchanger for performing heat exchange between the compressed gas component and the heat medium to liquefy the gas component; And a gas-liquid separator for separating the fluid passing through the heat exchanger into a liquid component and a gas component.

An evaporation gas supply line through which the evaporation gas supplied from the storage tank passes through the first compressor and the cooling device; and a second evaporation gas supply line through which the gas component generated in the cooling device is introduced into the second compressor, the heat exchanger, Liquid separator, and a recovery line for supplying the liquid component stored in the gas-liquid separator to the storage tank.

A merging line branching from said cooling device of said redistribution line and said second compressor and connected to said collection line to join some of the gaseous components produced in said cooling device to said collection line; A first fluid supply line connected to the cooling device for supplying a part of the merged fluid to the cooling device and a second fluid supply line for supplying a part of the gas components separated by the gas- Line. &Lt; / RTI >

Further comprising a processing unit that receives liquefied carbon dioxide from the storage tank and converts the temperature and pressure according to conditions of a customer, wherein the processing unit includes a primary heat exchanging unit for performing primary heat exchange between the liquefied carbon dioxide and the heating medium, And a secondary heat exchanger for performing secondary heat exchange between the pressurized liquefied carbon dioxide and the heat medium.

A liquefied gas supply line through which the liquefied carbon dioxide supplied from the storage tank is supplied to the customer through the primary heat exchanging unit, the pressurizing unit and the secondary heat exchanging unit; a hydrate suppressing unit for supplying the hydrate suppressing agent; And a hydrate inhibitor supply line that connects the liquefied gas supply line of the downstream end of the secondary heat exchange unit to each other to allow the hydrate inhibitor to be supplied to the liquefied gas supply line.

And a liquefied carbon dioxide vaporizer for supplying a portion of the liquefied carbon dioxide supplied from the storage tank to the customer for maintaining pressure in the storage tank, and supplying the vaporized liquefied carbon dioxide to the storage tank.

The carbon dioxide operation system according to the embodiment of the present invention can effectively perform carbon dioxide operation including liquefied carbon dioxide re-liquefaction.

The effects of the present invention are not limited to the effects mentioned above, and other effects not mentioned can be clearly understood by those skilled in the art from the description of the claims.

1 shows a carbon dioxide operating system according to an embodiment of the present invention.
FIG. 2 shows another example of the structure in which the internal pressure of the hydrate suppressing unit shown in FIG. 1 is maintained using the evaporated gas of liquefied carbon dioxide supplied from the storage tank.
FIG. 3 is a view showing a configuration for processing liquefied carbon dioxide remaining in a storage tank after unloading liquefied carbon dioxide into the carbon dioxide operating system shown in FIG. 1. FIG.
FIG. 4 is a flowchart of a carbon dioxide operation method using the carbon dioxide operation system shown in FIGS. 1 and 3. FIG.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. The embodiments described below are provided by way of example so that those skilled in the art will be able to fully understand the spirit of the present invention. The present invention is not limited to the embodiments described below, but may be embodied in other forms. In order to clearly explain the present invention, parts not related to the description are omitted from the drawings, and the width, length, thickness, etc. of the components may be exaggerated for convenience. Like reference numerals designate like elements throughout the specification.

Referring to FIG. 1, a carbon dioxide operating system 100 according to an embodiment of the present invention includes a storage tank 10 for storing liquefied carbon dioxide and evaporative gas of liquefied carbon dioxide, air for compressing air and supplying air to the storage tank 10 An inert gas device 120 for generating an inert gas from the air supplied from the air compressing unit 110 and supplying the generated inert gas to the storage tank 10, A remanent part 140 for re-liquefying the evaporated gas of the liquefied carbon dioxide supplied from the storage tank 10, a liquefied carbon dioxide supplying part 130 for supplying liquefied carbon dioxide from the storage tank 10, And a processing unit 150 for converting temperature and pressure according to the temperature and pressure. The carbon dioxide operation system 100 includes various types of liquefied gas carriers, regasification vessels, container ships, general merchant ships, LNG FPSO (Floating, Production, Storage and Off-loading), LNG FSRU (Floating Storage and Regasification Unit) And the like.

The storage tank 10 may include, for example, a membrane type tank, an SPB type tank, a pressure type tank, and the like.

The air compression unit 110 supplies compressed drying air to the storage tank 10 through the first supply line L1 in the liquefied carbon dioxide shipping process. An air filter 113 and an air heater 115 may be provided in the first supply line L1. The air filter 113 filters the compressed air supplied from the air compressor 110 to remove various impurities such as dust. The air heater 115 heats the air filtered by the air filter 113 according to the set temperature and supplies it to the storage tank 10. Therefore, before the liquefied carbon dioxide is shipped, the water present in the storage tank 10 can be effectively removed.

After the moisture is removed, a deactivation operation, which is a replacement process for discharging oxygen in the storage tank 10, is performed. To this end, the inert gas device 120 receives compressed air from the air compressor 110 through the second supply line L2 to generate an inert gas. At this time, the inert gas device 120 may generate an inert gas containing a large amount of nitrogen by burning oil and air or using a membrane device. The inert gas device 120 supplies the generated inert gas to the storage tank 10 and deactivates it. To this end, the second supply line L2 connects the air compression unit 110 with the inert gas device 120 and the first supply line L1. The inert gas supplied from the inert gas device 120 removes oxygen in the storage tank 10 to reduce the possibility of fire or explosion.

As described above, the compressed air provided by the air compression unit 110 can be effectively utilized for the water removal and deactivation work inside the storage tank 10.

After the deactivation operation is performed, a cooling operation inside the storage tank 10 is performed. The liquefied carbon dioxide supplied by the liquefied carbon dioxide supplying unit 130 is vaporized by the liquefied carbon dioxide vaporizer 135 and then injected into the storage tank 10 by an injection nozzle (not shown) provided in the storage tank 10 . The liquefied carbon dioxide supplying unit 130 supplies the liquefied carbon dioxide supplied from the liquefied carbon dioxide supplying unit 130 to the storage tank 10 through the liquefied carbon dioxide vaporizer 135 for the cooling operation in the storage tank 10, A vaporizer 135, and an injection line L11 connecting the storage tank 10 may be provided.

After the cooling operation is completed, the gas component existing in the storage tank 10 can be discharged to the outside. That is, since the temperature in the storage tank 10 into which the inert gas is injected is higher than the temperature of the liquefied carbon dioxide, when the liquefied carbon dioxide vaporized by the liquefied carbon dioxide vaporizer 135 is injected into the storage tank 10, Lt; / RTI > Accordingly, the evaporation gas and the inert gas may be present together in the storage tank 10, and such gas may be discharged to the outside through a discharge line (not shown).

The liquefied carbon dioxide supplied from the liquefied carbon dioxide supply unit 130 is supplied to the storage tank 10 through the third supply line L3 not through the liquefied carbon dioxide vaporizer 135. [ One end of the third supply line L3 is connected to the injection line L11 of the upstream end of the liquefied carbon dioxide vaporizer 135. The other end of the third supply line L3 is connected to the injection line L11 downstream of the liquefied carbon dioxide vaporizer 135. [ Lt; / RTI >

The re-cure unit 140 includes a first compressor 141 for compressing evaporative gas of liquefied carbon dioxide supplied from the storage tank 10, a cooling device 142 for cooling the evaporated gas compressed by the first compressor 141, A second compressor 143 for supplying and compressing the gas component generated by the cooling device 142, a heat exchanger for performing heat exchange between the compressed gas component supplied from the second compressor 143 and the heat medium to liquefy the gas component And a gas-liquid separator 147 for separating the fluid passing through the heat exchanger 145 and the heat exchanger 145 into a liquid component and a gaseous component.

The evaporation gas supply line L4 for allowing the evaporation gas supplied from the storage tank 10 to pass through the first compressor 141 and the cooling device 142, Liquid separator 147 is connected to a liquid recovery line L5 for passing the liquid component stored in the gas-liquid separator 147 to the storage tank 10 L6 may be provided. A portion of the gaseous components generated by the cooling device 142 is branched to the recovery line L6 and branched from the cooling device 142 of the redistribution line L5 and the second compressor 143 and connected to the recovery line L6, And a first fluid supply line L23 that branches from the recovery line L6 and is connected to the cooling device 142 and supplies the merged fluid to the cooling device 142 A second fluid supply line L27 for supplying a part of the gas components separated by the gas-liquid separator 147 to the cooling device 142 and a second fluid supply line L26 branched from the second fluid supply line L27, 147 may be provided with a discharge line L21 for discharging a part of the gas components separated by the discharge line L21.

That is, the evaporated gas supplied from the storage tank 10 is compressed through the first compressor 141 and then cooled by the cooling device 142 to be partially liquefied. The gas component discharged from the cooling device 142 is compressed and liquefied through the second compressor 143 and the heat exchanger 145 via the refueling line L5. At this time, some of the gas components discharged from the cooling device 142 are supplied to the collecting line L6 through the merging line L23. The heating medium used in the heat exchanger 145 may include a refrigerant (nitrogen, propane, propylene, ammonia, butane, butadiene or a mixture thereof), seawater, and the like.

Next, the fluid having passed through the heat exchanger 145 is separated into a gas component and a liquid component by the gas-liquid separator 147. The liquid component stored in the gas-liquid separator 147 is supplied to the storage tank 10 through the recovery line L6. At this time, the gas component discharged from the cooling device 142 supplied through the merging line L23 and the liquid component stored in the gas-liquid separator 147 discharged through the recovery line L6 are mixed. Some of the mixed fluid is supplied to the cooling device 142 through the first fluid supply line L26.

The gas component stored in the gas-liquid separator 147 is discharged to the outside through the discharge line L21, and a part of the gas component is supplied to the cooling device 142 through the second fluid supply line L27. The gas component discharged to the outside through the discharge line L21 mainly contains a large amount of nitrogen. Therefore, the nitrogen-extracted fluid can be stored again in the storage tank 10 through the recovery line L6 to effectively remove other components contained in the carbon dioxide.

The mixed fluid supplied to the cooling device 142 through the first fluid supply line L26 and the second fluid supply line L27 and the gas component supplied from the gas-liquid separator 147 are injected into the cooling device 142 And may be usefully used to cool the inside of the cooling device 142.

The processing unit 150 includes a primary heat exchanging unit 151 that performs primary heat exchange between the liquefied carbon dioxide and the heating medium, a pressurizing unit 153 that pressurizes the liquefied carbon dioxide subjected to the primary heat exchange and a pressurized liquefied carbon dioxide And a secondary heat exchanger 155 for performing secondary heat exchange. The primary heat exchanging unit 151, the pressurizing unit 153, and the secondary heat exchanging unit 155 may be provided in parallel according to the number of the storage tanks 10, the processing method, and the like, and the processing efficiency may be improved.

Here, a liquefied gas supply line L8 (see FIG. 8) for supplying the liquefied carbon dioxide fed from the storage tank 10 to the demand side 20 via the primary heat exchanging unit 151, the pressurizing unit 153 and the secondary heat exchanging unit 155 ) May be provided. The liquefied gas supply line L8 is provided with a liquefied carbon dioxide filter 170 to remove impurities contained in liquefied carbon dioxide through the treatment unit 150. [ The customer 20 may be, for example, a submarine reservoir, but may include various storage spaces for receiving and storing liquefied carbon dioxide from a ship.

As described above, the heat exchange is performed step by step through the primary and secondary heat exchangers 151 and 155 to maximize the performance of the heat exchanger 151 and 155, thereby achieving efficient operation. The heating medium used in the primary and secondary heat exchanging units 151 and 155 may include refrigerant (nitrogen, propane, propylene, ammonia, butane, butadiene or a mixture thereof), seawater, and the like.

The internal pressure of the storage tank 10 can be lowered in the process of processing the liquefied carbon dioxide stored in the storage tank 10 according to the conditions of the customer 20 and supplying it to the customer 20 through the liquefied gas supply line L8 have. This means that the pressure inside the storage tank 10 must be maintained in accordance with the set pressure, since the liquefied carbon dioxide may be solidified or rapidly vaporized and may affect the unloading of liquefied carbon dioxide.

Some of the liquefied carbon dioxide supplied from the storage tank 10 to the customer 20 is vaporized via the liquefied carbon dioxide vaporizer 135 and then supplied to the storage tank 10 for maintaining the pressure in the storage tank 10 A storage tank pressure maintaining line L12 branched from the liquefied gas supply line L8 at the upstream end of the processing unit 150 and connected to the injection line L11 at the upstream end of the liquefied carbon dioxide vaporizer 135 may be provided.

When the customer 20 is a submarine storage, a liquefied gas supply line (not shown) connecting the seabed storage due to low seawater temperature after unloading the liquefied carbon dioxide from the storage tank 10 to the customer 20 L8) may cause hydrate phenomenon. That is, ice may be generated in the liquefied gas supply line L8 and clogging may occur in the liquefied gas supply line L8.

A hydrate suppressing agent supply line L13 connecting the hydrate suppressing portion 160 and the liquefied gas supply line L8 at the rear end of the processing portion 150 from the hydrate suppressing portion 160 to the feed pump 162, The hydrate inhibitor may be supplied to the liquefied gas supply line L8. The hydrate inhibitor may include, for example, methanol, monoethylene glycol, triethylene glycol, and the like.

At this time, since the pressure inside the hydrate suppressing unit 160 is lowered by the supply of the hydrate inhibitor, it is necessary to keep the pressure inside the hydrate suppressing unit 160 constant according to the set pressure to smoothly supply the hydrate inhibitor .

For this purpose, the inert gas device 120 may provide an inert gas to the hydrate suppression unit 160 through the first hydrate suppression unit pressure maintaining line L14 in order to maintain the internal pressure of the hydrate suppression unit 160. Since the inert gas supplied by the inert gas device 120 is mainly composed of nitrogen, the possibility of fire and explosion of the hydrate suppression unit 160 is removed, the internal pressure is effectively maintained according to the set pressure, . Conventionally, the inert gas is discharged to the outside after being used for the deactivation operation, but the utilization of the inert gas can be enhanced through the embodiment of the present invention.

As another example, referring to FIG. 2, a second hydrate suppressing unit for maintaining the internal pressure of the hydrate suppressing unit 160 may include a second hydrate suppressing unit for maintaining evaporation gas of liquefied carbon dioxide from the storage tank 10 to the hydrate suppressing unit 160 A line L15 may be provided. Accordingly, utilization efficiency of the vaporized gas of liquefied carbon dioxide generated in the storage tank 10 can be increased to increase the operational efficiency.

On the other hand, there is a need to vaporize and discharge the liquefied carbon dioxide remaining in the storage tank 10 for the maintenance and maintenance work of the storage tank 10 after the liquefied carbon dioxide is supplied to the customer 20.

Referring to Figure 3, 1, the evaporated gas of liquefied carbon dioxide supplied from the storage tank 10 is compressed through the first compressor 141 to raise the temperature, and then the refrigerant is supplied to the storage tank 10, The evaporation gas can be returned to promote the vaporization of the liquefied carbon dioxide remaining in the storage tank 10. [ An evaporation facilitation line L16 may be provided for connecting the evaporation gas supply line L4 at the downstream end of the first compressor 141 and the recovery line L6 at the downstream end of the gas-liquid separator 147. [ The first compressor 141 is controlled such that the evaporated gas compressed through the first compressor 141 is supplied to the storage tank 10 through the evaporation facilitating line L16 and the recovery line L6 at the downstream end of the gas- And the cooling device 142 are closed and the second valve V2 provided in the evaporation promotion line L16 is controlled by a control unit (not shown) so that the second valve V2 is opened. The evaporated gas existing in the storage tank 10 may be discharged to the outside through a discharge line (not shown).

Hereinafter, a method for operating carbon dioxide using the carbon dioxide operating system 100 described above with reference to FIGS. 1 and 3 will be described with reference to FIG.

First, liquefied carbon dioxide is stored in the storage tank 10 (S1). This process (S1) can be performed during berths. Here, before storing the liquefied carbon dioxide, the compressed drying air is supplied to the storage tank 10 to remove the water in the storage tank 10, and the inert gas is supplied to the storage tank 10 to be inactivated , The process of vaporizing the liquefied carbon dioxide and injecting it into the storage tank 10 can be performed.

Next, the re-cure unit 140 re-liquefies the evaporated gas of the liquefied carbon dioxide stored in the storage tank 10 (S2). This process (S2) can be performed during ship operation.

Next, the liquefied carbon dioxide stored in the storage tank 10 is processed according to the conditions of the customer 20 and supplied to the consumer 20 through the liquefied gas supply line L8 (S3). This process (S3) can be performed in the liquefied carbon dioxide unloading process. Here, a process of supplying a portion of the liquefied carbon dioxide, which is supplied to the treatment unit 150, to the storage tank 10 for maintaining the pressure in the storage tank 10 may be performed.

Next, the hydrate inhibitor 160 is supplied with the hydrate inhibitor through the hydrate inhibitor supply line L13 to the liquefied gas supply line L8 at the rear end of the treatment unit 150 (S4). The process S4 may be performed during unloading or unloading of liquefied carbon dioxide. The pressure inside the hydrate restrainer 160 can be maintained by an inert gas supplied by the inert gas device 120 or a vaporized gas of liquefied carbon dioxide supplied from the storage tank 10.

1) between the storage tank 10 and the consumer 2 can be separated in a state in which the lock valve V3 (see Fig. 1) is closed. For reference, the binding site (P) is indicated by a dotted line for ease of understanding.

After the process S4, the evaporation gas supplied from the storage tank 10 is compressed and supplied to the storage tank 10 to convert the liquefied carbon dioxide remaining in the storage tank 10 into evaporated gas, To the outside can be performed. This can be performed for maintenance and maintenance work in the storage tank 10.

The foregoing has shown and described specific embodiments. However, it is to be understood that the present invention is not limited to the above-described embodiment, and various changes and modifications may be made without departing from the scope of the technical idea of the present invention described in the following claims It will be possible.

10: Storage tank 110: Air compression unit
120: Inert gas device 130: Liquefied carbon dioxide supply part
135: Liquefied carbon dioxide vaporizer 140: Re-
141: first compressor 142: cooling device
143: Second compressor 145: Heat exchanger
147: gas-liquid separator 150:
151: Primary heat exchanger 153:
155: Secondary heat exchanging unit 160: Hydrate suppressing unit
L4: Evaporative gas supply line L8: Liquefied gas supply line
L12: Storage tank pressure maintenance line L13: Hydrate inhibitor supply line
L14, L15: Hydrate suppression section pressure maintaining line L16: Evaporation promoting line

Claims

A storage tank for storing liquefied carbon dioxide and the vaporized gas of the liquefied carbon dioxide;
A first compressor for compressing the evaporated gas supplied from the storage tank;
A cooling device for cooling the compressed evaporated gas;
A second compressor for receiving and compressing gas components generated in the cooling device;
A heat exchanger for performing heat exchange between the compressed gas component and the heat medium to liquefy the gas component;
A gas-liquid separator for separating the fluid passing through the heat exchanger into a liquid component and a gas component;
A re-liquefaction line for allowing gas components generated in the cooling device to pass through the second compressor, the heat exchanger, and the gas-liquid separator;
A recovery line for supplying the liquid component stored in the gas-liquid separator to the storage tank;
A merging line which is branched from the cooling device of the redistribution line and the second compressor and is connected to the recovery line and joins some of the gas components generated in the cooling device to the recovery line;
A first fluid supply line branched from the recovery line and connected to the cooling device, for supplying a part of the merged fluid to the cooling device; And
And a second fluid supply line for supplying a part of the gas components separated by the gas-liquid separator to the cooling device.

delete

The method according to claim 1,
And a processor for supplying the liquefied carbon dioxide from the storage tank and converting temperature and pressure according to conditions of the customer,
Wherein the processing unit includes a primary heat exchanger for performing primary heat exchange between the liquefied carbon dioxide and the heat medium,
A pressurizing unit for pressurizing the liquefied carbon dioxide subjected to the primary heat exchange,
And a secondary heat exchanger for performing secondary heat exchange between the pressurized liquefied carbon dioxide and the heating medium.

5. The method of claim 4,
A liquefied gas supply line through which the liquefied carbon dioxide supplied from the storage tank is supplied to the customer through the primary heat exchanger, the pressurizer, and the secondary heat exchanger;
A hydrate suppressing portion for supplying a hydrate inhibitor,
And a hydrate inhibitor supply line for connecting the hydrate suppressing section and the liquefied gas supply line at the end of the secondary heat exchanging section to each other so that the hydrate inhibitor is supplied to the liquefied gas supply line.

5. The method of claim 4,
And a liquefied carbon dioxide vaporizer for supplying a portion of the liquefied carbon dioxide supplied from the storage tank to the customer for maintaining pressure in the storage tank and supplying the vaporized liquefied gas to the storage tank.