KR20130061706A - System for keeping high-pressure of storage container for pressurized liquefied natural gas - Google Patents

Abstract

PURPOSE: A system for maintaining the high pressure of a compressed LNG storage tank is provided to secure the stabilization of an unloading work by preventing the blockage of a nozzle and a pipe. CONSTITUTION: A system for maintaining the high pressure of a compressed LNG storage tank comprises an unloading line(410) and a pressure supplementary line(420). The unloading line is connected from the storage tank to a storage tank of a consumption site to unload compressed LNG. The pressure supplementary line is branched from the unloading line and supplies the compressed LNG to the storage tank by vaporizing some of the compressed LNG with a vaporizer.

Description

SYSTEM FOR KEEPING HIGH-PRESSURE OF STORAGE CONTAINER FOR PRESSURIZED LIQUEFIED NATURAL GAS}

The present invention relates to a high pressure maintaining system of a pressurized liquefied natural gas storage container, and prevents freezing of carbon dioxide due to pressure and temperature drop during unloading of the pressurized liquefied natural gas, and shortens the unloading time and maintains the efficiency of the storage container due to pressure retention. It relates to a high pressure maintenance system of a pressurized LNG storage container configured to increase this.

In general, liquefied natural gas (LNG) is a colorless transparent cryogenic liquid whose natural gas containing methane as its main component is cooled to cryogenic condition at -162 ℃ at atmospheric pressure, and its volume is reduced to one hundredth. It is known that it is economical for long distance transportation because it has better transport efficiency than gas state.

Such liquefied natural gas has been applied to large-scale and long-distance transportation in order to satisfy economic feasibility due to the high cost of construction of the production plant and the construction of carriers, whereas pipelines or compressed natural gas (CNG) for small- and short-haul transportation have been applied. Although it is known to have economic feasibility, transportation by pipelines is subject to geographical constraints, may cause problems of environmental destruction, and CNG has a disadvantage of low transportation efficiency.

On the other hand, natural gas has a liquefaction point of -163 ℃ at atmospheric pressure, the liquefaction point has a characteristic that rises under atmospheric pressure when a constant pressure is applied. This characteristic can reduce the processing steps such as removal of acid gas and fractionation of natural gas liquid (NGL) during the liquefaction process, which leads to a reduction in equipment and equipment capacity. It has the advantage of reducing the production cost of. Therefore, a plan has been devised to store and transport the liquefied natural gas pressurized at a constant pressure.

However, the pressurized liquefied natural gas produced by the pressurized cooling method has a problem that the pressure decreases as the amount of liquefied natural gas in the storage container decreases during unloading, which causes the temperature of the liquefied natural gas to fall. In addition, when the temperature and pressure of the liquefied natural gas stored in the storage container drops, a small amount of carbon dioxide (CO ₂ ) contained in the liquefied natural gas coagulates to block nozzles and pipes of the storage tank located at the consumer. Had a problem.

The present invention is to solve the conventional problems as described above, by preventing the pressure reduction of the storage container in which the pressurized liquefied natural gas is stored to prevent the clogging of the nozzle or pipe used for unloading the pressurized liquefied natural gas stable loading operation In this way, by reducing the electricity consumption and time required for unloading the pressurized liquefied natural gas, to ensure an efficient unloading system.

According to an aspect of the present invention for achieving the above object, a system for maintaining a high pressure of the pressurized liquefied natural gas storage container, the unloading to be connected to the storage tank of the consumer from the storage container to enable the unloading of the pressurized liquefied natural gas A pressure supplement line branched from the unloading line and connected to the storage container; And installed in the pressure fill line, and provides a high pressure maintaining system of the pressurized liquefied natural gas storage container comprising an evaporator for vaporizing the pressurized liquefied natural gas.

The unloading line is characterized in that the pressurized liquefied natural gas is unloaded to the storage tank only by the pressure of the pressurized liquefied natural gas.

The unloading line is characterized in that it is installed to extend from the top to the bottom of the storage tank.

The pressure filling line is connected to the upper portion of the storage container.

An evaporating gas line installed to supply the evaporating gas generated from the storage tank to the storage container; And a compressor installed in the boil-off gas line to compress the boil-off gas to be stored in the storage container.

The boil-off gas line is characterized in that connected to the top or bottom of the storage vessel.

Driving the compressor and the evaporator in conjunction; to adjust the set pressure inside the storage container when the amount of boil-off gas compressed by the compressor and supplied to the storage container cannot maintain the set pressure inside the storage container. It is characterized by increasing the load of the evaporator.

A system for maintaining a high pressure of a pressurized liquefied natural gas storage container, comprising a unloading line connected to a storage tank of a consumer from the storage container to enable unloading of the pressurized liquefied natural gas, and pressurized liquefied to be unloaded through the unloading line. Provided is a high pressure maintaining system of a pressurized liquefied natural gas storage container characterized in that a portion of the natural gas is vaporized and supplied to the storage container.

According to the present invention, the unloading of the pressurized liquefied natural gas prevents the freezing of carbon dioxide due to the pressure and temperature drop, thereby preventing the nozzles and pipes used for the unloading to be blocked, so that a stable unloading operation can be made, and the pressurized liquid Since the pump is not required for the unloading of natural gas, it is possible to reduce the cost by minimizing the unloading equipment, and to shorten the unloading time and increase efficiency by maintaining the pressure of the storage container.

1 is a flow chart showing a pressurized liquefied natural gas production method according to the present invention,
Figure 2 is a block diagram showing a pressurized liquefied natural gas production system according to the present invention,
3 is a flowchart illustrating a pressurized liquefied natural gas distribution method according to the present invention;
4 is a configuration diagram for explaining a pressurized liquefied natural gas distribution method according to the present invention;
Figure 5 is a side view showing a pressure vessel used in the pressurized liquefied natural gas distribution method according to the present invention,
6 is a configuration diagram for explaining another example of the pressurized liquefied natural gas distribution method according to the present invention;
7 is a perspective view showing a storage tank of liquefied natural gas according to the present invention;
8 is a perspective view showing various specifications for the storage tank of liquefied natural gas according to the present invention;
9 is a block diagram showing a storage tank of liquefied natural gas according to the present invention,
10 is a configuration diagram showing another example for a liquefied natural gas storage tank according to the present invention;
11 is a cross-sectional view showing a storage container of liquefied natural gas according to the first embodiment of the present invention;
12 is a cross-sectional view showing another embodiment of the connecting portion formed in the storage container of liquefied natural gas according to the first embodiment of the present invention;
13 is a cross-sectional view for explaining the operation of the storage container of liquefied natural gas according to the first embodiment of the present invention;
14 is a cross-sectional view showing a storage container of liquefied natural gas according to a second embodiment of the present invention;
15 is a cross-sectional view taken along the line AA ′ of FIG. 14;
16 is a cross-sectional view taken along the line BB ′ of FIG. 15;
17 is a cross-sectional view showing a storage container of liquefied natural gas according to a third embodiment of the present invention;
18 is a cross-sectional view showing a storage container of liquefied natural gas according to a fourth embodiment of the present invention;
19 is a cross-sectional view taken along the line CC ′ of FIG. 18;
20 is a cross-sectional view showing a storage container of liquefied natural gas according to a fifth embodiment of the present invention;
21 is a cross-sectional view showing a storage container of liquefied natural gas according to a sixth embodiment of the present invention;
22 is a cross-sectional view showing another example of a connection portion of a storage container of liquefied natural gas according to a sixth embodiment of the present invention;
23 is a cross-sectional view showing still another example of the connection of the storage container of liquefied natural gas according to the sixth embodiment of the present invention;
24 is a cross-sectional view showing still another example of a connection portion of a storage container of liquefied natural gas according to a sixth embodiment of the present invention;
25 is a configuration diagram showing an apparatus for producing liquefied natural gas according to the present invention;
26 is a side view showing a floating structure having a storage tank conveying device according to the present invention;
27 is a front view showing a floating structure having a storage tank conveying device according to the present invention;
28 is a side view for explaining the operation of the floating structure having a storage tank transport apparatus according to the present invention, and
29 is a block diagram showing a high pressure maintaining system of the pressurized liquefied natural gas storage container according to the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In addition, the following examples can be modified in various forms, and the scope of the present invention is not limited to the following examples.

In the drawings, like reference numerals refer to like elements throughout. The same reference numerals in the drawings denote like elements throughout the drawings.

1 is a flow chart illustrating a pressurized liquefied natural gas production method according to the present invention.

As shown in Figure 1, the pressurized liquefied natural gas production method according to the present invention is dehydrated without removing the acid gas from the natural gas supplied from the natural gas field (1), the natural gas is NGL (Natural Gas Liquid) Liquefaction is produced by pressure and cooling without fractionation to produce a pressurized liquefied natural gas, which may include a dehydration step (S11) and a liquefaction step (S12).

According to the dehydration step (S11), the natural gas is supplied from the natural gas field 1 to remove moisture such as steam by dehydration without the process of removing the acid gas. Therefore, natural gas may be dehydrated without undergoing acid gas removal, thereby simplifying the process and reducing investment and maintenance costs by eliminating acid gas removal. In addition, by sufficiently removing the water from the natural gas by the dehydration step (S11) to prevent the water freezing of the natural gas at the operating temperature and pressure of the production system.

According to the liquefaction step (S12), the natural gas after the dehydration step (S11) is liquefied to a pressure of 13 ~ 25bar and a temperature of -120 ~ -95 ℃ without the process of fractionating the Natural Gas Liquid (NGL) It will produce a liquefied natural gas, for example, can produce a pressurized liquefied natural gas having a pressure of 17 bar and a temperature of -115 ℃. Therefore, it is possible to simplify the production process of liquefied natural gas by omitting the fractionation process for NGL, that is, liquefied hydrocarbons, against natural gas, as well as to reduce power consumption for cooling and liquefying natural gas at a cryogenic temperature, And the maintenance cost can be reduced, thereby lowering the unit cost of the liquefied natural gas.

In the method of producing pressurized liquefied natural gas according to the present invention, the condition of the natural gas field 1 may be such that the calculated natural gas has less than 10% of carbon dioxide (CO ₂ ). In addition, when the carbon dioxide is present in less than 10% in the natural gas after the dehydration step (S11) may further include a carbon dioxide removal step (S13) for freezing and removing the carbon dioxide in the liquefaction step.

Carbon dioxide removal step (S13) may be carried out when the carbon dioxide in the natural gas after the dehydration step (S11) is more than 2% or less than 10%. Here, since natural gas exists in a liquid state at the temperature and pressure conditions of the pressurized liquefied natural gas which will be described later when carbon dioxide is 2% or less, the production and transportation of the pressurized liquefied natural gas are not affected even if the carbon dioxide removal step (S13) is not performed. If the carbon dioxide is more than 2% and less than 10% is frozen as a solid, the carbon dioxide is removed (S13) for liquefaction.

After the liquefaction step (S12), the storage step (S14) for storing the pressurized liquefied natural gas produced by the liquefaction step (S12) in a storage container of a dual structure can be carried out, whereby the pressurized liquefied natural gas is a desired position To this end, the transfer step (S15) may be carried out to transport through the vessel to the individual or packaged storage containers for this purpose. Of course, the strength of the tank may be transported through the vessel in a separate or packaged storage container for LNG transport.

Storage container used in the transfer step (S15) may have a material and structure to withstand the pressure of 13 ~ 25bar and the temperature of -120 ~ -95 ℃. In addition, a vessel for transporting a storage container may reduce a cost required for transporting a storage container by using a barge or a container ship without using a separate ship, such as a LNG carrier.

In this case, a barge or a container ship may be loaded and transported as it is or with minimal modification. Here, the storage vessels carried by the vessel may be transported in individual storage vessel units as required by the consumer.

On the other hand, the pressurized liquefied natural gas stored in the storage container supplied to the demand by completing the transfer step (S15) is to be supplied to the natural gas in the gas state through the regasification step (S16) at the final consumer. Here, the regasification facility for performing the regasification step (S16) may be composed of a high-pressure pump and a carburetor, in the case of individual unit consumption, such as power plants or factories may be provided with their own regasification facilities.

Figure 2 is a block diagram showing a pressurized liquefied natural gas production system according to the present invention.

As shown in Figure 2, the pressurized liquefied natural gas production system 10 according to the present invention is a natural dehydration equipment (11) for receiving and dehydrating natural gas supplied from the natural gas field (1), and natural through the dehydration equipment (11) It may include a liquefaction facility 12 for producing a pressurized liquefied natural gas by liquefying the gas at a pressure of 13 ~ 25bar and a temperature of -120 ~ -95 ℃.

The dehydration facility 11 receives natural gas from the natural gas field 1 to remove moisture such as water vapor by a dehydration process, thereby preventing freezing of natural gas at the operating temperature and pressure of the production system. At this time, the natural gas supplied from the natural gas field 1 to the dehydration facility 11 does not go through the process of removing acid gas, thereby simplifying the liquefied natural gas production process and investing and maintaining it. Help reduce costs

The liquefaction facility 12 is to liquefy the natural gas passed through the dehydration facility 11 at a pressure of 13 ~ 25bar and a temperature of -120 ~ -95 ℃ to produce a pressurized liquefied natural gas, for example a pressure of 17bar and -115 It may be to produce a pressurized liquefied natural gas having a temperature of ℃, it may include a compressor and a cooler required for the compression and cooling of low temperature fluid. Here, the natural gas that has passed through the dehydration facility (11) is supplied to the liquefaction facility (12) without the process of fractionating the NGL (Natural Gas Liquid) is passed through the liquefaction step, which is due to the fractionation process for NGL, ie liquefied hydrocarbons This reduces the cost of manufacturing and maintaining the system, thereby lowering the cost of liquefied natural gas.

The pressurized liquefied natural gas production system 10 according to the present invention removes carbon dioxide provided to freeze and remove carbon dioxide from natural gas when carbon dioxide is less than 10% in natural gas that has passed through the dehydration facility 11. It may further comprise a facility (13).

The carbon dioxide removal system 13 may perform removal of carbon dioxide from natural gas only when carbon dioxide exceeds 2% or 10% or less in the natural gas that has passed through the dehydration facility 11. In other words, natural gas exists in a liquid state at the temperature and pressure conditions of pressurized liquefied natural gas when carbon dioxide is 2% or less, so it is unnecessary to remove carbon dioxide, and carbon dioxide is frozen as a solid when carbon dioxide is more than 2% and 10% or less. It is necessary to remove carbon dioxide by the removal facility 13.

The pressurized liquefied natural gas produced from the liquefaction facility 12 is stored in a storage container of a dual structure in the storage facility 14 and transferred to a desired consumer by transport of the storage container.

3 is a flowchart illustrating a pressurized liquefied natural gas distribution method according to the present invention.

As shown in FIG. 3, the method for distributing a pressurized liquefied natural gas according to the present invention loads a storage container in which a pressurized liquefied natural gas liquefied by applying pressure to a natural gas and cools it, and transports the vessel to a consumer. The container is unloaded to the consumer and then the storage container is connected to the consumer regasification system. To this end, the pressurized liquefied natural gas distribution method according to the present invention may include a transfer step (S21), an unloading step (S22), and a connection step (S23).

As shown in Figure 4, according to the transfer step (S21), the pressurized liquefied natural gas liquefied natural gas at a pressure of 13 ~ 25bar and a temperature of -120 ~ -95 ℃ is stored and transportable container ( 21) is loaded on the vessel (2) to be transported to the consumer (3). Here, the pressurized liquefied natural gas may be produced by the above-described method of producing the pressurized liquefied natural gas, and the storage container 21 storing the same may use a natural gas at a pressure of 13 to 25 bar and a temperature of -120 to -95 ° C. With a material and structure that can withstand, it can be made of a double structure, and can be loaded in a large number on the vessel (2).

The transporting step S21 can transport the storage container 21 by a land transportation means such as a trailer or a train when the consumable product 3 is located inland.

The unloading step S22 is a step of unloading the storage container 21 filled with the pressurized liquefied natural gas by the unloading facility to the consumable paper when the ship 2 arrives at the consumable paper 3, As shown in FIG.

The connecting step S23 is a step of connecting the storage container 21 to the regasification system 23 of the consumer paper 3 so that the pressurized liquefied natural gas stored in the storage container 21 is vaporized. The natural gas generated by vaporizing the pressurized liquefied natural gas can be supplied to the consumer 3a. Meanwhile, as shown in FIG. 5, the storage container 21 is provided with a nozzle 21a for connecting to the vaporization line of the pressurized liquefied natural gas and the regasification system 23. Here, the nozzle 21a may be provided in various structures at various positions according to the posture in which the storage container 21 is loaded on the vessel 2 and the posture connected to the regasification system 23. It may have a connector that may be connected to the connector of the storage facility and the regasification system 23.

The distribution method of pressurized liquefied natural gas according to the present invention may further include a recovery step (S24) for recovering the empty storage container 21 from the consumption place (3).

Recovery step (S24) is to save the logistics cost by allowing the empty storage container 21 to be recovered to the place where the pressurized liquefied natural gas production system 10 is located by using the land transport means or the vessel (2), thereby natural gas May contribute to lowering the supply cost of

As shown in FIG. 6, in the transferring step S21, the container assembly 22 having a plurality of storage containers 21 packaged together may be transferred. Here, the container assembly 22 may be provided with an integrated nozzle 22a connected to each of the storage containers 21 to unify the nozzle 21a (shown in FIG. 5) provided for access of the pressurized liquefied natural gas. Therefore, the storage container 21 is configured by the container assembly 22 in a bundle unit, and the loading and unloading step S22 in the transfer step S21 by using the integrated nozzle 22a as a single container. It can reduce the time and effort required for unloading in the connection, connection with the regasification system 23 in the connection step (S23), and recovery in the recovery step (S24).

In the case of the container assembly 22, the storage container 21 is made up of a large number, so that it is efficient to be unloaded and used where a large amount of natural gas is required as a single consumption place, such as a power plant or an industrial complex.

In addition, according to the distribution method of the pressurized liquefied natural gas according to the present invention, there is an advantage that a separate storage tank is not required at the consumption place. In addition, only the regasification system needs to be provided, and the container 21 or the storage vessel 21 is circulated from the place where the pressurized liquefied natural gas production system 10 is located to each individual consumption place 3 by the vessel or the land transportation means in parallel with the vessel. The business of unloading the container assembly 22 and recovering the empty storage container 21 or the container assembly 22 is enabled. In particular, when a large number of small and medium-sized consumers are distributed on a large number of islands, such as Southeast Asia, it is possible to minimize the construction of infrastructure such as separate storage facilities and pipelines.

7 is a perspective view showing a storage tank of liquefied natural gas according to the present invention.

As shown in Figure 7, the storage tank 30 of the liquefied natural gas according to the present invention is provided with a plurality of storage containers 32 for storing the liquefied natural gas, respectively, inside the main body 31, the storage container (32) The loading and unloading of the liquefied natural gas to the storage container 32 is made possible through the loading and unloading line 33 which is connected to each and is provided with the loading and unloading valves 33a and 33b.

The main body 31 is provided so that a plurality of storage containers 32 are arranged inside, and the spacers 31a are installed between the storage containers 32 so that the storage containers 32 maintain the arrangement state while maintaining a space therebetween. ) May be included.

In addition, the main body 31 may have a heat insulating layer for blocking the entry and exit of temperature, or may have a double structure for heat insulation, may be made of a hexahedral structure, or in various other structures as in the present embodiment. In addition, the main body 31 may be provided with a plurality of support (31b) on the bottom in order to block the heat transfer of the ground by being spaced apart from the ground and to be installed in a stable posture on the ground.

As shown in Fig. 8, the main body 31 has a large, medium and small size standard as in (a), (b), (c) to standardize the number and size of the storage containers 32. In addition, the present invention is not limited thereto, and may accommodate various numbers of storage containers 32 and may be manufactured in various standards.

Storage container 32 may be made of a structure or material that withstands a pressure of 13 ~ 25bar and a temperature of -120 ~ -95 ℃ with a loading and unloading line 33 to be described later to be stored liquefied natural gas, respectively. Therefore, the storage container 32 and the unloading line 33 has a double structure, such as a heat insulating material is installed to withstand such pressure and temperature conditions, the pressure of 13 ~ 25bar and the temperature of -120 ~ -95 ℃, For example, it enables the storage and transportation of pressurized liquefied natural gas having a pressure of 17 bar and a temperature of -115 ° C.

As shown in FIG. 9, the loading and unloading line 33 is connected to each of the storage containers 32 and extends to the outside of the main body 31, so that the loading and unloading of the liquefied natural gas to the storage container 32 is performed. Unloading valves 33a and 33b for opening and closing are provided. Therefore, after the main body 31 is installed in the consumer place, when the loading and unloading line 33 is connected to the regasification system, supply line, etc. of the consumer place, supply of liquefied natural gas or natural gas is immediately possible.

Here, the unloading valves 33a and 33b are provided to the first individual valve 33a and the storage container 32 all individually installed to open and close the loading and unloading of the liquefied natural gas to each of the storage containers 32. It may include a first integrated valve 33b which is installed to open and close the unloading and unloading of the natural liquefied natural gas, each storage container is one if the first individual valve 33a is opened as the unloading valve It can also be packaged into a single tank. Moreover, only the 1st individual valve 33a may be provided, or only the 1st integrated valve 33b may be provided and used.

* The storage tank 30 of the liquefied natural gas according to the present invention is connected to some or all of the storage container 32 to the outside of the main body 31 in order to discharge the boil-off gas naturally generated from the storage container 32. In addition to being installed to extend, the boil-off gas line (34a, 34b) for opening and closing the discharge of the boil-off gas (BOG) generated in the storage container 32 may be further included. Here, the boil-off gas line 34 may be made of a structure or material that withstands a pressure of 13 ~ 25bar and a temperature of -120 ~ -95 ℃.

In addition, the boil-off gas valves 34a and 34b are second individual valves 34a that are individually installed to open and close the discharge of the boil-off gas to each of the storage containers 32 and the boil-off gas to all the storage containers 32. It may include a second integrated valve 34b which is installed to open and close the discharge of the integrated, only the second individual valve 34a, or only the second integrated valve 34b may be installed as the boil-off gas valve. . Here, as described above, if all of the second individual valves 34a are opened, each storage container may be packaged as one and may be used as one tank. Also, only the second individual valve 34a may be installed, or only the first integrated valve 34b may be installed and used.

The storage tank 30 of the liquefied natural gas according to the present invention measures the internal pressure for each or all of the storage containers 32 and outputs it from the pressure sensing unit 35 and the pressure sensing unit 35 to output the detection signal. The controller 36 may further include a controller 36 configured to receive the detection signal and to display the internal pressure for each or all of the storage containers 32 to the outside of the main body 31 through the display unit 37. Here, the pressure sensing unit 35 is installed at the front end of the storage container 32 in the loading and unloading line 33, respectively, for example, in order to measure the internal pressure for each or all of the storage containers 32, or the loading and unloading line. In (33) it may be installed on an integrated route which travels for the loading and unloading of liquefied natural gas. In addition, the control unit 36 is provided on the main body 31 or the unloading valves 33a and 33b and the boil-off gas valves 34a, in accordance with an operation signal output from the operation unit 36a provided for wired and wireless communication at a remote location. 34b) can be controlled respectively.

As shown in FIG. 10, the storage tank 30 of the liquefied natural gas according to the present invention is used to control the heating value required in the vaporization and consumption of the liquefied natural gas discharged from the storage container 32. Heating unit 38 is installed to vaporize the liquefied natural gas unloaded from some or all of the storage container 32, and the calorific value control unit 39 is installed to adjust the calorific value of the natural gas passing through the heating unit 38 It may include. Here, the heating unit 38 and the calorific value control unit 39 are installed on a line in which any one or many of the storage containers 32 are integrated in the loading and unloading line 33, or the storage container 32 and the loading and unloading unit. Connected to the line 33 may be installed in a separate line to pass the liquefied natural gas by the valve.

The heating unit 38 is a plate fin type heat exchanger 38a which is installed to primarily heat the liquefied natural gas by heat exchange with air, and the liquefied natural gas vaporized by passing through the heat exchanger 38a. It may include an electric heater 38b that is installed to heat differentially.

The line where the calorific value control unit 39 is installed, for example, the loading and unloading line 33, may further include a bypass line 41 connected to bypass the calorific value control unit 39 by the bypass valve 41a. have. Therefore, when it is necessary to adjust the calorific value for the natural gas, the natural gas is supplied to the calorific value control unit 39 by the operation of the bypass valve 41a so that natural gas having the calorific value required by the consumer is supplied, When it is unnecessary to adjust the amount of heat generated for the gas, the natural gas may bypass the heat amount adjusting unit 39 through the bypass line 41 by the operation of the bypass valve 41a. Here, the bypass valve 41a may be composed of a three-way valve or a plurality of bidirectional valves.

In addition, the storage tank 30 of the liquefied natural gas according to the present invention has a temperature sensing unit 42 for sensing the temperature of the natural gas to be unloaded, so that the natural gas to be unloaded has a temperature required by the consumer, and the temperature The controller 36 may further include a controller 36 that receives the signal from the detector 42 and controls the electric heater 38b to reach the set temperature range. The controller 36 may display the temperature of the natural gas being unloaded to the outside of the main body 31 through the display unit 37.

The temperature sensing unit 42 may be installed at the exit side of the loading and unloading line 33. In addition, the controller 36 may control the bypass valve 41a described above according to the operation signal of the operation unit 36a.

As described above, the storage tank 30 of the liquefied natural gas according to the present invention has a storage container 32 capable of storing and treating boil-off gas according to a function, and a storage container capable of controlling vaporization facilities and calorific value as well as storing and treating boil-off gas. It can be divided into (32), allowing easy transport of liquefied natural gas or natural gas to meet the consumer's needs.

11 is a cross-sectional view showing a storage container of liquefied natural gas according to the first embodiment of the present invention.

As shown in FIG. 11, the storage container 50 of the liquefied natural gas according to the first embodiment of the present invention includes an inner shell 51 and an inner shell made of a metal that withstands low temperature of the liquefied natural gas stored therein. A heat insulation layer part 53 may be installed to reduce heat transfer between the outer shell 52 made of a steel material to withstand the inner pressure by wrapping the outer side of the 51.

The inner shell 51 forms a space for storing liquefied natural gas therein, and has a low temperature characteristic such as aluminum, stainless steel, 5-9% nickel steel, etc. It may be made in the form of a tube, as in the present embodiment, or may have various shapes including other polyhedrons.

The outer shell 52 surrounds the outside of the inner shell 51 to form a space between the inner shell 51 and is made of a steel material to withstand the inner pressure, and the inner pressure applied to the inner shell 51. By sharing the internal shell 51 to reduce the amount of material used to reduce the manufacturing cost.

Since the inner shell 51 has the same or approximate pressure of the inner shell and the heat insulating layer portion by the connecting flow path described later, the pressure of the pressurized liquefied natural gas can be supported by the outer shell. Thus, even if the inner shell 51 is made to withstand temperatures of -120 to -95 DEG C, the above-mentioned pressure (13-25 bar) and temperature conditions by the inner shell and the outer shell, for example, a pressure of 17 bar and -115 DEG C. It is possible to store the pressurized liquefied natural gas having a temperature of, and may be designed to satisfy the above pressure and temperature conditions in a state in which the outer shell 52 and the heat insulating layer part 53 are assembled.

On the other hand, the inner shell 51 may be formed to have a small thickness (t1) compared to the thickness (t2) of the outer shell 52, thereby reducing the use of expensive metal having excellent low-temperature characteristics when manufacturing.

The heat insulation layer part 53 is installed in the space between the inner shell 51 and the outer shell 52, and consists of a heat insulating material which reduces heat transfer. In addition, the structure or material design may be made so that the same pressure as the pressure in the inner shell 51 is applied to the heat insulating layer part 53, where the same pressure as the pressure in the inner shell 51 means the same degree of rigidity. It does not mean to include a similar degree.

The interior of the heat insulation layer portion 53 and the inner shell 51 may be connected to each other by a connection flow passage 54 for pressure equalization between the inner shell 51 and the outer shell. This connection flow path 54 causes pressure equalization in and out of the inner shell 51 (inside of the outer shell 52), and the outer shell 52 supports a significant portion of the pressure to prevent the inner shell 51. The thickness can be reduced.

As shown in FIG. 12, the connection passage 54 may be formed at a side where the heat insulation layer part 53 is in contact with the connection part 55 provided at the entrance and exit 51a of the inner shell 51. Therefore, the pressure in the inner shell 51 moves toward the heat insulation layer part 53 through the connecting flow passage 54 so that the pressure is balanced between the inside and the outside of the inner cell 51.

As shown in FIG. 13, heat transfer is reduced between an inner shell 51 made of a metal having excellent low temperature characteristics and an outer shell 52 made of a high strength steel, while maintaining an appropriate BOR (Boil Off Rate). By installing a heat insulating layer 53 having a thickness so as to enable the storage of not only liquefied natural gas but also pressurized liquefied natural gas, and the thickness of the inner shell 51 due to the pressure balance between the inside and the outside of the inner shell 51. By reducing (t1), it is possible to reduce the use of expensive metals having excellent low temperature properties. In addition, the occurrence of structural defects due to the internal pressure of the inner shell 51 can be prevented, and the storage container 50 excellent in durability can be provided.

On the other hand, the connection portion 55 is connected to be integrally connected to the entrance and exit 51a formed for supply and discharge of the liquefied natural gas in the inner shell 51 is provided to protrude to the outside of the outer shell 52, such as an external member such as a valve May be connected.

14 is a cross-sectional view showing a storage container of liquefied natural gas according to a second embodiment of the present invention. As shown in FIG. 14, the storage container 60 for liquefied natural gas according to the second embodiment of the present invention surrounds the inner shell 61 and the outer shell 61 in which the liquefied natural gas is stored inside. Between the outer shell 62 is provided a support 63 for supporting the inner shell 61 and the outer shell 62 and a heat insulation layer portion 64 for reducing heat transfer. Meanwhile, in order to supply and discharge the liquefied natural gas to the inner shell 61, a connection part (not shown) may be integrally connected to the entrance and exit of the inner shell 61 to protrude to the outside of the outer shell 62. An external member such as a valve may be connected to the connection portion.

The inner shell 61 forms a space for storing the liquefied natural gas inside, and the metal having excellent low temperature characteristics such as aluminum, stainless steel, 5-9% nickel steel, etc. It may be made, as in the present embodiment may be made in the form of a tube, or may have a variety of shapes, including other polyhedra.

The outer shell 62 surrounds the outside of the inner shell 61 to form a space between the inner shell 61 and may be made of a steel material to withstand the internal pressure, and the inner portion applied to the inner shell 61. By sharing the pressure, the amount of material used in the inner shell 61 may be reduced, thereby reducing the manufacturing cost.

Since the inner shell 61 is equal to or close to the pressure of the inner shell and the heat insulating layer by the connection flow path, the pressure of the pressurized liquefied natural gas can be supported by the outer shell. Thus, even if the inner shell 61 is made to withstand temperatures of -120 to -95 ° C, the above-mentioned pressure (13-25 bar) and temperature conditions by the inner shell and the outer shell, for example, a pressure of 17 bar and -115 ° C It is possible to store the pressurized liquefied natural gas having a temperature of, and may be designed to satisfy the above pressure and temperature conditions in an assembled state of the outer shell 62, the support 63, and the heat insulating layer 64.

The support 63 is installed in the space between the inner shell 61 and the outer shell 62 to support the inner shell 61 and the outer shell 62 to structurally secure the inner shell 61 and the outer shell 62. Reinforcement, and may be made of a metal (eg, low temperature steel) to withstand the low temperature of liquefied natural gas, and as shown in FIG. 15, a single along the side circumference of the inner shell 61 and the outer shell 62. It may be installed in a plurality, or in a plurality of spaced apart up and down at the sides of the inner shell 61 and the outer shell 62 as in this embodiment.

As shown in FIG. 16, the support 63 includes first and second flanges 63a and 63b supported on the outer side of the inner shell 61 and the inner side of the outer shell 62, and the first and second flanges 63a and 63b. It may include a first web (Webc) 63c provided between the second flange (63lang, 63b). Here, each of the first and second flanges 63a and 63b may be formed in a ring shape or may be formed of a curvature member in which a plurality of ring shapes are divided.

In addition, the support 63 may be fixedly supported by welding to the outer surface of the inner shell 61 and the inner surface of the outer shell 62 without using a separate member such as a flange. In this case, glass fibers may be inserted into the support to prevent heat from being transferred to the outside through the support.

The first web 63c may be formed of a plurality of gratings whose ends are fixed to the first and second flanges 63a and 63b, respectively. Here, the grating may be fixed so that a part is mainly subjected to a compressive force between the first and second flanges 63a and 62b, and the other may be fixed to form a truss structure, and the shape and the fixing position may be changed or adjusted. The same applies when the web 63c is fixedly supported by welding to the inner and outer shells.

An insulation member 65 may be installed between the inner surface of the outer shell 62 and the second flange 63b to block heat transfer. Here, the heat insulating member 65 may be made of glass fiber, and prevents the temperature of the inner shell 61 from being transferred to the outer shell 62 by the support 63.

In addition, when the support 63 is fixed by welding, a heat insulating member such as glass fiber is disposed at the end of the support 63 in contact with the outer shell 62 and then fixed by welding, or a separate heat insulating member is provided. It may be arranged between the outside of the support and the inside of the outer shell to prevent the temperature of the inner shell 61 from being transmitted to the outer shell 62 by the support 63.

The storage container 60 of liquefied natural gas according to the present invention is a lower support 66 which is installed in the lower space between the inner shell 61 and the outer shell 62 to support the inner shell 61 and the outer shell 62. ) May be further included. Here, the lower support 66 is the third and fourth flanges supported on the outer surface of the inner shell 61 and the inner surface of the outer shell 62 and the second web provided between the third and fourth flanges, respectively. The second web may include a plurality of gratings having both ends fixed to the third and fourth flanges, respectively, and for these components, the support 63 may be different from the specific shape according to the installation position. The contrasting components are the same. In addition, a heat insulating member (not shown) may be installed between the inner surface of the outer shell 62 and the fourth flange to block thermal shear. Here, the heat insulating member may be made of glass fiber.

The heat insulation layer part 64 is installed in the space between the inner shell 61 and the outer shell 62, and consists of a heat insulating material which reduces heat transfer. In addition, the design can be made so that the same pressure as the pressure in the inner shell 61 is applied to the heat insulating layer portion 64, where the same pressure as the pressure in the inner shell 61 does not mean exactly the same. In addition, the heat insulating layer 64 and the inside of the inner shell 61 are connected to each other as in the previous embodiment shown in FIG. 12 to balance pressure between the inside and outside of the inner shell 61. (54; shown in FIG. 12), and the connection flow path 54 has been described in detail in the previous embodiment, and thus description thereof will be omitted.

In addition, the heat insulating layer portion 64 may be made of a heat insulating material (eg, perlite) in the form of grains (eg, perlite) that may pass through the support 63, particularly the web 63 c of the grating structure. Therefore, when filling, the insulating layer 64 in the form of particles may be freely mixed and filled so that a gap does not occur between the inner shell 61 and the outer shell 62 and thus the insulation performance may be excellent.

In addition, since the support 63 and the lower support 66 of the grating support structure system is filled, the particle flow of the heat insulating layer 64 is freed, and thus, the heterogeneity of the heat insulating layer 64 may be prevented.

As shown in Fig. 17, the storage vessel 70 of the liquefied natural gas according to the third embodiment of the present invention may be installed in the transverse direction, in which case the lower support 66 in the previous embodiment (Fig. 14). ) Can be omitted.

18 is a cross-sectional view showing a storage container of liquefied natural gas according to a fourth embodiment of the present invention.

As shown in FIG. 18, the storage container 80 of liquefied natural gas according to the fourth embodiment of the present invention surrounds the inner shell 81 and the outer shell 81 in which the liquefied natural gas is stored. A heat insulation layer portion 84 is provided between the outer shells 82 to reduce heat transfer, and the outer surface of the inner shell 81 and the inner surface of the outer shell 82 are connected by metal cores 83. On the other hand, for the supply and discharge of the liquefied natural gas to the inner shell 81, the connection portion (not shown) is integrally connected to the entrance and exit of the inner shell 81 may protrude out of the outer shell 82, such An external member such as a valve may be connected to the connection portion.

The inner shell 81 forms a space for storing the liquefied natural gas therein, and has a low temperature characteristic such as aluminum, stainless steel, 5 to 9% nickel steel, etc. It may be made, as in the present embodiment may be made in the form of a tube, or may have a variety of shapes, including other polyhedra.

The outer shell 82 surrounds the outside of the inner shell 81 to form a space between the inner shell 81 and may be made of a steel material to withstand the internal pressure, and the inner portion applied to the inner shell 81. By sharing the pressure, the material of the inner shell 81 can be saved, thereby reducing the manufacturing cost.

Since the inner shell 81 is equal to or close to the pressure of the inner shell and the heat insulating layer by the connecting flow path, the pressure of the pressurized liquefied natural gas can be supported by the outer shell. Thus, even if the inner shell 81 is made to withstand temperatures of -120 to -95 DEG C, the pressures (13-25 bar) and temperature conditions described above by the inner shell and the outer shell, for example, a pressure of 17 bar and -115 DEG C. It is possible to store the pressurized liquefied natural gas having a temperature of, and may be designed to satisfy the above pressure and temperature conditions in the state in which the outer shell 82, the metal core 83, and the heat insulation layer portion 84 are assembled. .

The metal core 83 is connected to the outer side of the inner shell 81 and the inner side of the outer shell 82 so that the inner shell 81 and the outer shell 82 are supported by each other, and the inner shell 81 and the outer side thereof. It may be installed along the circumference of the side of the shell 82, and may be installed in a plurality at intervals up and down at the sides of the inner shell 81 and the outer shell 82 as in this embodiment. The metal padding 83 may be formed of a wire such as a steel wire. Here, the metal core 83 is connected to, for example, a plurality of rings provided on the outer surface of the inner shell 81 and the inner surface of the outer shell 82, or fastened or welded to the support points 83a provided on the plurality. In addition, the inner shell 81 and the outer shell 82 may be connected in various ways.

As shown in FIG. 19, the metal core 83 is connected to two support points 83a of the adjacent outer shell 82 while one support point 83a of the inner shell 81 is connected to the outer shell 82. One support point 83a may be repeatedly installed to be connected to two support points 83a of the adjacent inner shell 81, and may be connected to be arranged in a zigzag along the circumference between the inner shell 81 and the outer shell 82. And, as in (a) and (b), the number of connections to the number can vary.

The storage container 80 of liquefied natural gas according to the present invention is a lower support 86 which is installed in the lower space between the inner shell 81 and the outer shell 82 to support the inner shell 81 and the outer shell 82. ) May be further included. Here, the lower support 86 may include a flange which is respectively supported on the outer surface of the inner shell 81 and the inner surface of the outer shell 82, and a web provided between the flanges, both ends of the web being on the flange. It may be composed of a plurality of gratings each fixed, these components are the same as the lower support 66 of the storage container 60 of the liquefied natural gas according to the third embodiment will be omitted.

The heat insulation layer part 84 is installed in the space between the inner shell 81 and the outer shell 82, and consists of a heat insulating material which reduces heat transfer. In addition, the structure or material design may be made so that the same pressure as the pressure in the inner shell 81 is applied to the heat insulation layer portion 84, where the same pressure as the pressure in the inner shell 81 is the same in strict meaning. It also includes cases of minor differences. In addition, the thermal insulation layer portion 84 and the inner shell 81 are connected to the connecting flow path 54 (shown in FIG. 12) as in the previous embodiment shown in FIG. 12 to balance the pressure between the inner shell 81 and the outer side. It can be connected to each other by, and since the connection flow path 54 has been described in detail in the previous embodiment will not be described.

The heat insulation layer part 84 may be made of a heat insulating material having a grain shape that may pass through the metal core 83. Accordingly, the filling of the insulating layer portion 84 in the form of particles can be freely mixed evenly filled so that there is no gap between the inner shell 81 and the outer shell 82 to prevent the heterogeneity of the insulating layer portion 84 is excellent Have insulation performance.

As shown in FIG. 20, the storage vessel 90 of liquefied natural gas according to the present invention may be installed in the transverse direction, in which case the lower support 86 (FIG. 18) in the previous embodiment may be omitted. have.

21 is a cross-sectional view showing a storage container of liquefied natural gas according to a sixth embodiment of the present invention.

As shown in FIG. 21, the storage container 100 for liquefied natural gas according to the sixth embodiment of the present invention includes an inner shell 110 and an inner shell 110 made of a metal for enduring low temperature of the liquefied natural gas. Between the outer shell 120 surrounding the outer side is provided with a heat insulating layer 130 for reducing heat transfer, the connection portion 140 is provided on the inner shell 110 and the outer shell 120, the connection portion 140 At the end of the injection portion 141 extending outward from the inner shell 110, a first flange 142 for flange connection in contact with the valve 4 is provided, and the injection portion 141 is provided from the outer shell 120. A second flange 144 is formed at the end of the extension 143 extending to surround the valve (4) for flange connection to the valve (4).

The inner shell 110 forms a space for storing the liquefied natural gas inside, and has a low temperature property such as aluminum, stainless steel, 5-9% nickel steel, etc. It may be made in the form of a tube, as in the present embodiment, or may have various shapes including other polyhedrons.

The outer shell 120 surrounds the outer side of the inner shell 110 to form a space between the inner shell 110 and may be made of a steel material to withstand the inner pressure and the inner pressure applied to the inner shell 110. By reducing the cost of the inner shell 110 to reduce the material production cost.

Since the inner shell 110 has the same or approximate pressure of the inner shell and the heat insulating layer by the connection flow path, the pressure of the liquefied natural gas can be supported by the outer shell. Thus, even if the inner shell 110 is made to withstand temperatures of -120 to -95 ° C, the pressure (13-25 bar) and temperature conditions described above, such as 17 bar and -115 ° C, are achieved by the inner shell and the outer shell. It is possible to store the pressurized liquefied natural gas having a temperature of, and may be designed to satisfy the above pressure and temperature conditions in an assembled state of the outer shell 120 and the heat insulating layer 130.

On the other hand, the inner shell 110 may be formed to have a smaller thickness than the thickness of the outer shell 120, thereby reducing the use of expensive metal having excellent low-temperature characteristics when manufacturing.

The heat insulation layer part 130 is installed in the space between the inner shell 110 and the outer shell 120 and is made of a heat insulating material to reduce heat transfer. In addition, a structure or a material design may be made to apply the same pressure as the pressure in the inner shell 110 to the heat insulation layer part 130. Here, the same pressure as the pressure in the inner shell 110 is the same in the exact sense. But a bit more pressure is also applicable.

The inside of the heat insulating layer 130 and the inner shell 110 may be connected to each other by a connection flow path (not shown) for the pressure balance between the inner shell 110 and the outside. Here, the connection flow path may include various embodiments capable of providing a flow path such as a hole, a pipe, or the like, and may include, for example, a hole formed in the injection part 141 of the connection part 140. Therefore, the pressure in the inner shell 110 is moved to the heat insulation layer portion 130 side through the connection flow path so that the internal pressure of the inner cell 110 and the internal pressure of the heat insulation layer portion 130 are balanced.

The connection part 140 is connected to the flow path between the injection part 141 and the valve 4 by the first flange 142 is in direct contact with the valve 4 and flanged by the bolt 181 and the nut 182. , Since the injection portion 141 and the first flange 142 directly contact the liquefied natural gas, the same material as the inner shell 110, for example, a metal having excellent low temperature characteristics, such as aluminum, stainless steel, 5-9% nickel steel, or the like. Can be done.

In addition, the connecting portion 140, as in the present embodiment, the extension portion 143 wraps the outside of the injection portion 141 at intervals, the second flange 144 is sandwiched between the first flange 142 valve 4 ) May be flanged to the bolt 181 and the nut 182, and the extension 143 and the second flange 144 may be made of steel.

As shown in FIG. 22, the connection part 150 is integrally formed with the injection part 151 by screwing the first flange 152 to the injection part 151.

As shown in FIG. 23, the connection part 160 may allow the first flange 162 to be fixed to the injection part 161 with a fastening member 163 such as a bolt or a screw. Here, the fastening member 163 may be fastened in a circumferential direction to the coupling portion 163a formed at the end of the injection portion 161 through the first flange 162.

When using a bolt as the fastening member 163, as shown in Fig. 23 (a), a female thread is machined on the coupling part 163a and the first flange 162, and the first flange is bolted with a separate male thread. 162 and the injection section 161a, where the head of the bolt with male thread can accommodate the head of the bolt in the first flange 162 to avoid interference with the surrounding members. The shape of the shape can be processed.

However, if the head of the bolt is configured to come out of the first flange as shown in Fig. 23 (b) to accommodate the head of the bolt on the valve 4 side to avoid interference between the head of the bolt and the surrounding members The bolt head shape should be machined and fastened to the first flange.

As shown in FIG. 24, the connection portion 170 is formed by the bolt 181 and the nut 182 with the second flange 174 positioned at the edge of the first flange 172 and in contact with the valve 4. Flange can be connected. In this case, the first flanges 172 may be coupled to each other only by bolts 183 to the valve 4.

25 is a configuration diagram showing an apparatus for producing liquefied natural gas according to the present invention.

In the apparatus 200 for producing liquefied natural gas according to the present invention, a heat exchanger 230 is installed in each of the first branch lines 221 branched from the supply line 220 of natural gas, respectively, and the heat exchanger 230. Cools the natural gas supplied through the first branch line 221 using the refrigerant supplied from the refrigerant supply unit 210 and removes the carbon dioxide condensed on each of the heat exchangers 230 by the regeneration unit 240. Regeneration fluid is supplied in place of natural gas.

Apparatus 200 for producing liquefied natural gas according to the present invention is not only liquefied natural gas, but also pressurized liquefied natural gas pressurized at a constant pressure, for example, pressurized liquefied natural cooled to -120 to -95 ° C at a pressure of 13 to 25 bar. It can also be used for the production of gases.

The refrigerant supply unit 210 supplies the refrigerant for heat exchange with natural gas to the heat exchanger 230 so that the natural gas is liquefied in the heat exchanger 230.

The heat exchanger 230 is installed in each of the first branch line 221 branched from the supply line 220 of the natural gas to a plurality of them are connected in parallel to each other, the refrigerant is supplied to the natural gas supplied from the supply line 220 Cooling by heat exchange with the refrigerant supplied from the supply unit 210, the total capacity exceeds the liquefied natural gas production can be made to maintain one or a plurality of atmospheric conditions during the production of the liquefied natural gas.

The number and capacity of the heat exchanger 230 may be determined in consideration of the liquefied natural gas production of the entire plant, for example, in the case of the heat exchanger 230 that can cover 20% of the total liquefied natural gas production A stand can be provided, five of them can be operated, and the rest can be kept in a standby state. This configuration allows the carbon dioxide to be shut down for the frozen heat exchanger and the standby heat exchanger can be operated while the frozen carbon dioxide is removed, thereby keeping the total yield of liquefied natural gas in the entire plant constant.

The regeneration unit 240 selectively supplies each of the heat exchangers 230 with a regeneration fluid for removing condensed carbon dioxide in place of natural gas. In addition, the regeneration unit 240 is a regeneration fluid supply unit 241 for supplying a regeneration fluid and a regeneration fluid connected to the front and rear ends of the heat exchanger 230 in each of the first branch lines 221 from the regeneration fluid supply unit 241. A first valve 243 installed at a front end and a rear end of a fluid line 242 and a portion where the regeneration fluid line 242 is connected at each of the first branch lines 221, and a heat exchanger at the regeneration fluid line 242. The second valve 244 may be installed at the front and rear ends of each of the groups 230.

Here, the regeneration fluid supply unit 241 may use, for example, high temperature air as the regeneration fluid, and supply the high temperature air to the heat exchanger 230 using pressure or pumping force to convert the condensed carbon dioxide into a liquid or gas state. It can be removed by changing the phase.

The apparatus 200 for producing liquefied natural gas according to the present invention includes a heat exchanger 230 for checking the freezing of carbon dioxide for each of the heat exchangers 230 and controlling supply of regeneration fluid to each of the heat exchangers 230. Receiving the detection signal output from each of the detection unit 250 and the detection unit 250, which is installed to confirm the freezing of carbon dioxide for each of the first and second valves (243, 244) and the regeneration fluid supply unit (241) The control unit 260 may further include a control unit.

The control unit 260 checks the heat exchanger 230 in which freezing of carbon dioxide is generated from the detection signal output from the detection unit 250, and in order to supply the regeneration fluid to the heat exchanger 230, first, the first valve ( Blocking the supply of natural gas to the heat exchanger 230 by blocking 243, the regeneration fluid is supplied to the heat exchanger 230 by driving the regeneration fluid supply unit 241 and opening of the second valve 244, Carbon dioxide frozen in the heat exchanger 230 by the regeneration fluid is liquefied or vaporized to be removed. On the other hand, the control unit 260 may count the regeneration fluid by the timer to supply the heat exchanger 230 until the set time is over.

The sensing unit 250 may be formed as a flow meter for measuring the flow rate of the liquefied natural gas that is installed at the rear end of the heat exchanger 230 in each of the first branch lines 221 as in this embodiment. Therefore, when the flow rate value measured by the detector 250, which is a flow meter, is lower than or equal to the set value, it may be determined that freezing of carbon dioxide occurs in the corresponding heat exchanger 230.

In addition to the flow meter, the detection unit 250 may be installed in each of the first branch lines 221, and may be configured as a carbon dioxide measuring device for measuring the content of carbon dioxide contained in the gas at the front and rear ends of the heat exchanger 230. When the difference in the amount of carbon dioxide contained in the gas measured at the front and rear of the unit 230 is greater than or equal to the set amount, it may be determined that freezing of the carbon dioxide occurs in the heat exchanger 230.

Apparatus 200 for producing liquefied natural gas according to the present invention is a refrigerant line 211 for supplying a refrigerant from the refrigerant supply unit 210 to the heat exchanger 230 in order to stop the operation of the heat exchanger 230 in which freezing of carbon dioxide has occurred. ) Further includes a third valve 270 installed at a front end and a rear end of each of the heat exchangers 230. Here, the third valve 270 may be controlled by the control unit 260, for example, the control unit 260 is the front end and the rear end of the heat exchanger 230, the carbon dioxide is frozen through the detection unit 250 By blocking the third valve 270 positioned in the to stop the operation of the heat exchanger 230 in which carbon dioxide is frozen.

26 and 27 are side and front views of a floating structure having a storage tank conveying device according to the present invention.

As shown in Figures 26 and 27, the floating structure 300 having the transport device of the storage tank according to the present invention is a transport device of the storage tank on the floating structure 320 is installed to float at sea by buoyancy. 310 is installed. Here, the floating structure 320 may be a structure made of a barge type, or a vessel capable of sailing using its own thrust.

In the transportation device 310 of the storage tank according to the present invention, the rail 312 is provided along the moving direction of the storage tank 330 on the mounting table 311a which is lifted by the lifting unit 311, and the storage tank ( The transport cart 313 on which the 330 is loaded is installed to be movable along the rail 312.

By doing so, it is possible to reduce the impact on the storage tank than to carry the storage tank by using a crane or the like. In addition, by connecting a plurality of storage tanks, a large amount of cargo can be transported over a long distance, and thus other transportation in terms of cost. More efficient than means. Also, this is not a way of lifting and moving storage tanks, so it will be more effective for the movement of relatively heavy storage tanks.

Although the storage device 310 of the storage tank according to the present invention has been shown to be installed in the floating structure 320 as in this embodiment, it is not limited thereto, and may be fixed to the ground or installed in various other transportation devices.

The storage tank 330 may store liquefied natural gas or liquefied natural gas pressurized at a constant pressure, and various cargoes may be stored. On the other hand, the pressurized liquefied natural gas may be a natural gas liquefied at a pressure of 13 ~ 25bar and a temperature of -120 ~ -95 ℃, for the storage of the pressurized liquefied natural gas storage tank 330 at low temperature and pressure It can be made of a material and a structure to sufficiently endure.

In addition, the storage tank 330 is manufactured in a dual structure to store the liquefied natural gas or the liquefied natural gas pressurized at a constant pressure, and as described above, the internal pressure of the dual structure and the pressure inside the storage tank 330 are balanced. It is also possible to have a connection channel between the dual structure of the storage tank and the interior of the storage tank to achieve.

As shown in FIG. 28, the elevating unit 311 elevates the mounting table 311a up and down. For example, the lifting section 311a may elevate the mounting table 311a from the floating structure 320 to the upper surface of the quay wall 5. have. Here, the mounting table 311a may be installed by moving downwards on the hinge coupling portion 311c of the lower end on one side or both sides to open the moving platform 311b to provide a movement path of the transport cart 313. .

The moving scaffold 311b serves to limit the movement of the conveyance trolley 313 when folded upward, and when the loading table 311a rises to the same height as the height of the quay wall 5 by the lifting section 311. The transport cart 313 serves to safely move to the land by helping the connection between the quay wall 5 and the loading table 311a. In addition, the movable footrest 311b may be provided with an auxiliary rail 311d connected to the rail 312 on a surface facing upward when unfolded downward.

In addition, the lifting unit 311 may be used in various structures and actuators for the lifting of the mounting table 311a, for example, a plurality of coupling slidingly coupled to the upper and lower to the lower portion of the mounting table 311a By connecting to the lower portion of the member or the mounting table 311a to each other by the link member can be installed so that the mounting table 311 is movable up and down by a plurality of link members, such as stretched up and down in the rotational direction, for a linear motion The mounting table 311a may be raised and lowered by using an actuator such as a motor that provides a driving force or a cylinder operated by hydraulic pressure.

The rail 312 is installed along the moving direction of the storage tank 330 on the mounting table 311a, and is formed in a pair, and has the same width as the rail (not shown) of the train located on the inner wall 5. It can be arranged side by side to have. Therefore, when the conveyance trolley 313 raised by the elevating part 311 to the upper surface of the quay wall 5 moves along the rail 312 and moves to the rail on the quay wall 5, it is remoted by a land transportation device such as a train. It is possible to move.

The transport cart 313 is provided with a plurality of wheels 313a movable along the rails 312 at the lower part, and a storage tank 330 is loaded at the upper part, and one or both sides for connection of other transport carts 313. The connection portion may be provided. In addition, the transport cart 313 is equipped with a storage tank 330 may be provided with a tank guard 313b of steel material for protecting the storage tank 330 from corrosion and external impact on the upper surface.

The feed cart 313 may be moved along the rail 312 by driving the winch, for example, by being connected to the winch through a cable, but not limited thereto, and conveying a rotational force to some or all of the wheels 313a. The driving unit (not shown) may travel along the rail 312 by magnetic force.

29 is a block diagram showing a high pressure maintaining system of the pressurized liquefied natural gas storage container according to the present invention. As shown in FIG. 29, the high pressure maintaining system 400 of the pressurized liquefied natural gas storage container according to the present invention is connected to the storage tank 6 of the consumer from the storage container 411 to unload the pressurized liquefied natural gas. Including the unloading line 410, the supply of a portion of the pressurized liquefied natural gas to be unloaded through the unloading line 410 to the storage container 411, for this purpose, the pressure supplement line 420 and the evaporator 430 ) May be further included.

The unloading line 410 is connected to the storage tank 6 of the consumer from the storage container 411 to enable the unloading of the pressurized liquefied natural gas, and pressurized liquefied natural only by the pressure of the pressurized liquefied natural gas stored in the storage container 411. It is possible to allow the gas to be unloaded into the storage tank 6. In addition, by installing the unloading line 410 to extend from the upper portion to the lower portion of the storage tank 6, the pressurized liquefied natural gas can be unloaded to the storage tank 6 only by the pressure of the pressurized liquefied natural gas stored in the storage container 411. In addition, it is possible to minimize the generation of boil-off gas.

Pressure supplement line 420 is branched from the unloading line 410 is connected to the storage container 411, the evaporator 430 is installed. In addition, the pressure filling line 420 may be connected to the upper portion of the storage container 411, so that the natural gas supplied to the storage container 411 through the pressure filling line 420 may increase the pressure in the storage container 411. Keep it constant.

The evaporator 430 vaporizes the pressurized liquefied natural gas supplied through the pressure supplement line 420 to be supplied to the storage container 411. Therefore, the natural gas vaporized by the evaporator 430 is supplied to the storage container 411 through the pressure supplement line 420 to increase the pressure in the storage container 411 which is reduced during the initial unloading of the pressurized liquefied natural gas. Therefore, the pressure in the storage container 411 is maintained above the bubble point pressure of the liquefied natural gas.

The high pressure maintaining system 400 of the pressurized liquefied natural gas storage container according to the present invention recovers the evaporated gas generated in the storage tank of the consumer, so as to maintain the pressure in the storage container 411 above the bubble point pressure of the liquefied natural gas. The evaporation gas line 440 and the compressor 450 may be further included.

The boil-off gas line 440 is connected to the storage vessel 411 so that the boil-off gas generated from the storage tank 6 is supplied to the storage vessel 411, preferably an upper portion (not shown) of the storage vessel 411 or It can be connected to the bottom.

The pressure drop in the storage vessel 411 generated during the initial unloading of the LNG is compensated by the evaporator 430, and after that, the boil gas and the unloading gas of the natural gas stored in the storage tank 6 are unloaded. The evaporated gas generated through the replenishment is sent to the storage container 411.

In addition, the compressor 450 is installed in the boil-off gas line 440 and compresses the boil-off gas supplied along the boil-off gas line 440 to be stored in the storage container 411. Therefore, while unloading the pressurized liquefied natural gas, the evaporated gas generated in the storage tank 6 is pressurized through the compressor 450 through the evaporation gas line 440 and then injected into the storage container 411 to pressurized liquefied natural gas. Can improve the transportation efficiency.

In addition, according to the high pressure maintaining system 400 of the pressurized liquefied natural gas storage container according to the present invention, the evaporator 430 and the compressor 450 may complement each other. For example, when the compressor 450 does not function properly, the load of the evaporator 430 is increased to maintain the storage container 411 at a constant pressure, and when the evaporator 430 does not function properly, the compressor ( As the load of 450 increases, the pressure of the storage container 411 is kept constant.

The present invention is not limited to the above embodiments and can be implemented in various modifications or variations without departing from the technical spirit of the present invention in one of ordinary skill in the art to which the present invention pertains. It is self-evident.

1: natural gas field 2: ship
3: consumer 3a: consumer
4: valve 5: quay
6: storage tank
10: pressurized liquefied natural gas production system
11: dehydration equipment 12: carbon dioxide removal equipment
13: liquefaction facility 14: storage facility
21: storage container 21a: nozzle
22: container assembly 22a: integrated nozzle
23: regasification system 30: storage tank of liquefied natural gas
31: body 31a: spacer
31b: support 32: storage container
33: Unloading line 33a, 33b: Unloading valve
34: boil off gas line 34a, 34b: boil off gas valve
35 pressure sensing unit 36 control unit
36a: operation unit 37: display unit
38: heating part 38a: heat exchanger
38b: electric heater 39: calorific value control unit
41: bypass line 41a: bypass valve
42: temperature detection unit 50: storage container
51: inner shell 51a: doorway
52 outer shell 53 heat insulation layer
54: connection path 55: connection part
60,70: storage container 61: inner shell
62: outer shell 63: support
63a: first flange 63b: second flange
63c: first web 64: heat insulation layer portion
65: heat insulation member 66: lower support
80,90: storage container 81: inner shell
82: outer shell 83: metal core
83a: support point 84: heat insulation layer
86: lower support 100: storage container
110: inner shell 120: outer shell
130: heat insulating layer 140,150,160,170: connection
141,151,161: injection part 142,152,162,172: first flange
143: extension 144,174: second flange
163: fastening member 163a: coupling portion
181,183: bolt 182: nut
200: production device of pressurized liquefied natural gas 210: refrigerant supply unit
211: refrigerant line 220: supply line
221: first branch line 230: heat exchanger
240: regeneration unit 241: regeneration fluid supply unit
242: regeneration fluid line 243: first valve
244: second valve 250: detector
260 control unit 270 third valve
300: floating structure having a storage tank transport device
310: conveying device of the storage tank 311: lifting unit
311a: Loading Table 311b: Moving Scaffold
311c: hinge coupling portion 311d: auxiliary rail
312: rail 313: feed cart
313a: Wheel 313b: Tank Guard
320: floating structure 330: storage tank
400: high pressure maintenance system of pressurized liquefied natural gas storage container
410: unloading line 411: storage container
420: pressure fill line 430: evaporator
440: boil-off gas line 450: compressor

Claims (5)

A system for maintaining a high pressure of a pressurized LNG storage container,
An unloading line connected to a storage tank of a consumption place from the storage container to unload the pressurized liquefied natural gas; And
And a pressure supplement line branched from the unloading line to vaporize at least a portion of the pressurized liquefied natural gas with an evaporator and to supply the storage container.
The pressurized liquefied natural gas is supplied with natural gas from a natural gas field and dehydrated without removing acidic gas, and a pressure of 13 to 25 bar and a temperature of -120 to -95 ° C without fractionating NGL (Natural Gas Liquid). Produced by liquefaction,
Pressurized liquefied natural gas, characterized in that to prevent the freezing of carbon dioxide contained in the pressurized liquefied natural gas by maintaining the pressure of the storage container through the pressure filling line when the pressurized liquefied natural gas from the storage container High pressure holding system of storage vessel. The method of claim 1,
The pressurized liquefied natural gas is a high pressure maintenance system of the pressurized liquefied natural gas storage container, characterized in that the pressure of the storage vessel is maintained by the pressure of the pressurized liquefied natural gas to be unloaded to the storage tank through the loading line. The method of claim 1,
The unloading line is installed to extend from the top to the bottom of the storage tank,
The pressure supplement line is a high pressure maintenance system of the pressurized liquefied natural gas storage container, characterized in that connected to the upper portion of the storage container. The method of claim 1,
An evaporation gas line for supplying the evaporation gas generated from the storage tank to the storage container; And
It is provided in the boil-off gas line, further comprising a compressor for compressing boil-off gas,
If the amount of boil-off gas compressed by the compressor and supplied to the storage container cannot maintain the set pressure inside the storage container, the set pressure inside the storage container is adjusted. High pressure maintenance system of the pressurized liquefied natural gas storage container, characterized in that to increase the load of the evaporator. The method of claim 1,
The storage container is a dual structure consisting of an inner shell made of a metal that withstands the low temperature of the liquefied natural gas, and an outer shell made of a steel material that withstands the internal pressure applied to the inner shell, the space between the inner shell and the outer shell High pressure maintenance system of the pressurized liquefied natural gas storage container, characterized in that the heat insulating layer is installed to reduce heat transfer.

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