KR101955473B1 - Liquefied gas regasification system - Google Patents

Abstract

Disclosed is a liquefied gas regasification system to improve regasification efficiency and performance of liquefied gas. According to one embodiment of the present invention, the liquefied gas regasification system comprises: a first regasification line to allow liquefied gas supplied from a storage tank to be regasified, heated, and supplied to a customer by heat exchange with a thermal medium through first and second heat exchangers in order; a second regasification line to allow the liquefied gas to be regasified, heated, and supplied to the customer by heat exchange with a thermal medium through third and fourth heat exchangers in order; a first circulation line to circulate a thermal medium supplied from a first suction drum to the first suction drum through the first and third heat exchangers; and a second circulation line branched from the rear end of the first suction drum of the first circulation line to join a part distributed from the thermal medium supplied from the first suction drum between the first suction drum of the first circulation line and a branch position through the second and fourth heat exchangers, and including a second suction drum for storing the thermal medium liquefied through the fourth heat exchanger. The first suction drum stores the thermal medium with a first pressure liquefied through the third heat exchanger and the second suction drum stores the thermal medium with a second pressure higher than the first pressure.

Description

[0001] LIQUEFIED GAS REGASIFICATION SYSTEM [0002]

The present invention relates to a liquefied gas regeneration system, and more particularly, to a liquefied gas regeneration system that vaporizes, processes, and supplies a liquefied gas to a customer.

Liquefied natural gas is a colorless transparent cryogenic liquid with a volume reduced to 1/600 by cooling the natural gas collected from the gas field to an ultra-low temperature of about -162 degrees centigrade. Liquefied natural gas is transported and unloaded from a production site to a consumer over a long distance by a liquefied natural gas carrier. The unloaded liquefied natural gas is regenerated by a liquefied natural gas regeneration facility installed in the land terminal, and then supplied to the demand sites such as homes and industrial complexes.

The land terminal with such regeneration facilities can be economically advantageous when constructed in a natural gas market and where demand is stable. However, in the case of demand where natural gas demand is seasonally, short-term, or periodically limited, construction of land terminals is uneconomical due to high installation and maintenance costs.

Recently, LNG RV (LNG Regasification Vessel) or LNG Regasification Vessel (LNG Regasification Vessel) or LNG Regasification Vessel (LNG Regasification Vessel), which is equipped with a re-gasification system in a liquefied natural gas carrier to supply natural gas directly to customers, And natural gas storage and regasification unit (FSRU) have been developed and operated.

Such a regasification system or regasification facility vaporizes liquefied natural gas by heat exchange the cryogenic liquefied natural gas contained within the storage tank with a heat source such as a seawater.

However, when the seawater is directly heat-exchanged with the liquefied natural gas, the durability of the regeneration facility is significantly lowered due to freezing of seawater or corrosion of the equipment due to salt. In addition, since the temperature of seawater is not constant, reliability of liquefied natural gas regeneration performance may be deteriorated. As a related art, refer to Korean Patent Laid-Open No. 10-2008-0085284 (published on Mar. 24, 2008).

Korean Patent Laid-Open No. 10-2008-0085284 (disclosed on September 24, 2008)

An embodiment of the present invention seeks to provide a liquefied gas regeneration system that improves regeneration efficiency and performance of liquefied gas.

According to an aspect of the present invention, a first regeneration line is provided for allowing liquefied gas supplied from a storage tank to be regenerated and increased in temperature by sequentially exchanging heat with a heating medium through a first heat exchanger and a second heat exchanger, and supplied to a customer; A second regeneration line for allowing the liquefied gas to be regenerated and heated by heat exchange with the heat medium through the third heat exchanger and the fourth heat exchanger in sequence and to be supplied to the customer; A first circulation line circulating the heat medium supplied from the first suction drum through the first heat exchanger and the third heat exchanger to the first suction drum; And a branched portion of the heat medium supplied from the first suction drum is branched from the rear end of the first suction drum of the first circulation line through the second heat exchanger and the fourth heat exchanger, And a second suction line which joins the first suction drum and the branch point and stores the liquefied heat medium via the fourth heat exchanger, wherein the first suction drum is connected to the third heat exchanger And the second suction drum stores a heating medium having a second pressure higher than the first pressure, wherein the second suction drum stores a heating medium having a first liquefied first pressure, and the second suction drum stores a heating medium having a second pressure higher than the first pressure.

Wherein the first circulation line is provided between the first suction drum and the merging point and includes a heating medium pump for pressurizing the heating medium supplied from the first suction drum and a heating medium supplied to the first heat exchanger from the pressurized heating medium A first heater for heat-exchanging the reduced heating medium with a heat source and sending the reduced heat medium to the first heat exchanger in a vaporized state, and a second heat exchanger for exchanging heat with the heat source through the first heat exchanger to the third heat exchanger 2 heater can be provided.

The second circulation line includes a third heater for heat-exchanging the heat medium supplied to the second heat exchanger among the heat medium supplied from the first suction drum to a heat source, and a fourth heater for heat-exchanging the heat medium through the second heat exchanger with the heat source. The heating medium pump is provided with a heating medium supplied from the first suction drum so as to maintain the state of the heating medium passing through the third heating device in a liquid phase, It can be pressurized according to the set pressure.

The liquefied gas regeneration system according to the embodiment of the present invention can improve the regeneration efficiency and performance of the liquefied gas.

The heating mediums having different pressures are divided and stored in the first suction drum and the second suction drum provided in the respective circulation lines and are pressurized and circulated by the pumps provided in the respective circulation lines, It is possible to reduce the electricity consumed by the pump and efficiently operate the liquefied gas regeneration system.

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 is a conceptual diagram showing a liquefied gas regeneration system according to an embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. The following embodiments are provided to fully convey the spirit of the present invention to a person having ordinary skill in the art to which the present invention belongs. The present invention is not limited to the embodiments shown herein but may be embodied in other forms. For the sake of clarity, the drawings are not drawn to scale, and the size of the elements may be slightly exaggerated to facilitate understanding.

1 is a conceptual diagram showing a liquefied gas regeneration system 100 according to an embodiment of the present invention.

1, a liquefied gas regeneration system 100 according to an embodiment of the present invention is a system in which liquefied gas supplied from a storage tank 110 is supplied to a first heat exchanger 131 and a second heat exchanger 132 sequentially A first regeneration line 121 for allowing the liquefied gas to flow into the third heat exchanger 133 and the fourth heat exchanger 134 A second regeneration line 122 for regenerating and raising the temperature by heat exchange with the heating medium and supplying it to the customer 190, and a second regeneration line 122 for supplying the heating medium supplied from the first suction drum 161 to the first heat exchanger A first circulation line L1 for circulating the first suction drum 131 to the first suction drum 161 through the third heat exchanger 133 and a second circulation line L1 for circulating the first suction drum 161 from the rear end of the first suction drum 161 And the divided portion of the heat medium supplied from the first suction drum 161 flows through the second heat exchanger 132 and the fourth heat exchanger 134 A second suction drum 162 which joins the first suction drum 161 of the first circulation line L1 and the branch point D1 and stores the liquefied heat medium via the fourth heat exchanger 134; 2 circulation line L2.

Here, the first suction drum 161 stores the heating medium having the liquefied first pressure via the third heat exchanger 133, and the second suction drum 162 stores the liquid medium having the second pressure higher than the first pressure, Can store the heating medium.

The first circulation line L1 is provided between the first suction drum 161 and the confluence point D2 and includes a heating medium pump 151 for pressurizing the heating medium supplied from the first suction drum 161, A pressure reducing valve 140 for reducing the pressure of the heating medium supplied to the first heat exchanger 131 among the heating mediums pressurized by the heating medium pump 151 and a heat medium which is reduced in pressure by the pressure reducing valve 140 to heat- And a second heater 142 for sending the heat medium to the third heat exchanger 133 by heat-exchanging the heat medium with the heat source through the first heat exchanger 131 and the first heater 141 to the first heat exchanger 131 do.

The second circulation line L2 includes a third heater 143 for exchanging heat with the heat source supplied to the second heat exchanger 132 among the heat medium supplied from the first suction drum 161, A fourth heater 144 for exchanging the heat medium with the heat source through the first suction drum 132 and a pressurizing pump 152 for pressing the heat medium supplied from the second suction drum 162 are provided.

Here, the heating medium pump 151 can pressurize the heating medium supplied from the first suction drum 161 according to the set pressure so that the state of the heating medium passing through the third heater 143 is maintained in a liquid state.

Such a liquefied gas regeneration system 100 can be used for a variety of liquefied fuel carriers, liquefied fuel RVs (Regasification Vessels), container ships, general merchant ships, LNG FPSO (Floating, Production, Storage and Off-loading), LNG FSRU Unit) and so on.

In the embodiments of the present invention, liquefied natural gas and natural gas regenerated therefrom have been described in order to facilitate understanding of the present invention, but the present invention is not limited thereto. For example, in another embodiment, various liquefied gases such as liquefied ethane gas, liquefied hydrocarbon gas, and regasified vaporized gas may be applied.

Hereinafter, each component will be described in detail.

The storage tank 110 may include a membrane type tank, an SPB type tank, and the like, which store the fuel in a liquefied state while maintaining an adiabatic state. The liquefied gas stored in the storage tank 110 may be any one of Liquefied Natural Gas (LNG), Liquefied Petroleum Gas (LPG), Dimethylether (DME), and Ethane which can be stored in a liquefied state, but is not limited thereto . In the storage tank 110, a feed pump 123 may be provided to supply the liquefied natural gas to the regeneration line 120.

The regasification line (120) regenerates the liquefied natural gas into natural gas and supplies it to the customer (190). Here, the customer 190 may include a consuming place for consuming natural gas such as a land-based home, an industrial complex, or various facilities using hydrocarbon as fuel gas.

This regasification line 120 branches the liquefied natural gas into a first regasification line 121 and a second regasification line 122, which independently regenerate and heat up the natural gas to supply it to the customer 190 .

The feed pump 124 provided in the regasification line 120 may press at least one of the liquefied natural gas carried along the first regasification line 121 and the second regasification line 122. The feed pump 124 is operable to regulate at least one of the liquefied natural gas transported along the first regasification line 121 and the second regasification line 122 to a pressure level of the natural gas required by the customer 190, It can be pressurized to a pressure level suitable for regasification of the gas.

The feed pump 124 is connected to the first regeneration line 121 and the second regeneration line 122 on the regasification line 120 in order to reduce facility construction costs and improve facility operation efficiency. But there is no limitation to this. For example, in other embodiments, the feed pump 124 may be provided on the upstream side of the heat exchanger on the first regasification line 121 and on the second regasification line 122, respectively.

The first regasification line 121 regenerates and raises the liquefied natural gas pressurized by the supply pump 124 through the first heat exchanger 131 and the second heat exchanger 132 in sequence and then circulates the natural gas ).

The second regasification line 122 regenerates and warms the liquefied natural gas pressurized by the supply pump 124 through the third heat exchanger 133 and the fourth heat exchanger 134 in sequence and then circulates the natural gas ).

To this end, the inlet side end of the reclaim line 120 described above is connected to a storage tank 110, which receives liquefied natural gas, and at a stop, a first regasification line 121 and a second regasification line 122, And the first regeneration line 121 and the second regeneration line 122 at the outlet side end can rejoin and be connected to the customer 190 requiring natural gas.

A flow regulating valve (not shown) is also provided at the point where the first regasification line 121 and the second regasification line 122 branch off, although not shown, so that the first regasification line 121 and the second regeneration line 122, The supply and supply amount of the liquefied natural gas flowing into the line 122 can be adjusted.

The first heat exchanger 131 and the second heat exchanger 132 are sequentially provided in the first regeneration line 121. The first heat exchanger 131 and the second heat exchanger 132 sequentially heat-exchange the liquefied natural gas and the heating medium transferred along the first regeneration line 121 to regenerate liquefied natural hydrogen into natural gas The temperature of the natural gas required by the customer 190 can be raised.

Here, the heating medium may be formed of a condensable heat transfer medium which facilitates phase change between vapor and liquid phase. The heating medium may include, for example, propane which is easily available from the cost side and can easily control the phase change between the gas phase and the liquid phase. However, the present invention is not limited thereto, and may include various condensing heat transfer media that can effectively perform heat exchange between the heat source and the natural gas while facilitating the phase change between the gas and the liquid phase.

The first heat exchanger 131 exchanges heat between the liquefied natural gas conveyed along the first regeneration line 121 and the heat medium circulating along the first circulation line L1 to convert the liquefied natural gas into low temperature natural gas Gas can be regenerated. Here, the heating medium can heat-exchange with the liquefied natural gas in the gaseous state.

The second heat exchanger 132 exchanges heat between the vaporized low-temperature natural gas that has passed through the first heat exchanger 131 of the first regeneration line 121 and the heat medium that circulates along the second circulation line L2 to each other , The low temperature natural gas can be raised to a level corresponding to the natural gas temperature condition required by the customer 190. Here, the heating medium can heat-exchange with the liquefied natural gas in a liquid state.

The third heat exchanger 133 and the fourth heat exchanger 134 are sequentially provided in the second regeneration line 122. The third heat exchanger 133 and the fourth heat exchanger 134 successively heat-exchange the liquefied natural gas and the heating medium transferred along the second regeneration line 122 to regenerate liquefied natural hydrogen into natural gas The temperature of the natural gas required by the customer 190 can be raised.

The third heat exchanger 133 exchanges heat between the liquefied natural gas conveyed along the second regasification line 122 and the heat medium circulating along the first circulation line L1 to convert the liquefied natural gas into low temperature natural gas Can be regenerated. The heating medium having passed through the third heat exchanger 133 may be liquefied and stored in the first suction drum 161.

The fourth heat exchanger 134 exchanges heat between the vaporized low temperature natural gas that has passed through the third heat exchanger 133 of the second regeneration line 122 and the heat medium that circulates along the second circulation line L2 to each other , The low temperature natural gas can be raised to a level corresponding to the natural gas temperature condition required by the customer 190. The heating medium having passed through the fourth heat exchanger 133 may be liquefied and stored in the second suction drum 162.

The heating medium pump 151 of the first circulation line L1 presses the heating medium supplied from the first suction drum 161. [ For example, the heating medium pump 151 may pressurize the heating medium to a pressure level of about 7 to 8 bar. However, the present invention is not limited thereto, and the pressure level of the heating medium pump 151 may be variously changed depending on the components of the heating medium or the temperature condition of the natural gas required by the customer 190.

The heating medium pump 151 is connected to the first suction drum 161 so as to perform heat exchange with the low temperature natural gas in the second heat exchanger 132 while the heating medium having passed through the third heater 143 is maintained in a liquid state without phase change, It is possible to pressurize the supplied heat medium to about 9 barg.

The heating medium pump 151 may be provided to prevent a malfunction and a failure, and to receive and operate a liquid heating medium for stable pressurization of the heating medium. The inlet side end of the first circulation line L1 is connected to the lower side of the first suction drum 161 so that only the liquid heating medium can be supplied to the heating medium pump 151. [

The pressure reducing valve 140 reduces the pressure of the heating medium supplied to the first heat exchanger 131 among the heating mediums pressurized by the heating medium pump 151. The pressure reducing valve 140 may, for example, reduce the pressure of the heating medium to a pressure level of about 2 to 3 bar. However, the present invention is not limited thereto. The heating medium flowing through the first circulation line L1 may be vaporized while passing through the first heater 141, re-liquefied through the first heat exchanger 131, 142 may be vaporized and passed through the third heat exchanger 133 to be re-liquefied, the pressure may be reduced to various ranges of pressure levels.

The first heater 141 heat-exchanges the heating medium, which is reduced in pressure by the pressure reducing valve 140, with the heat source and sends the heat to the first heat exchanger 131. At this time, the heating medium is vaporized by the first heater 141. The heat source may include seawater, steam, and the like. In the embodiment of the present invention, sea water is used as a heat source.

The second heater 142 exchanges heat with the heat source through the first heat exchanger 131 and sends it to the third heat exchanger 133. The heating medium having passed through the second heater 142 is stored in the first suction drum 161 in a liquefied state via the third heat exchanger 133.

The third heater 143 of the second circulation line L2 heats the liquid heating medium supplied to the two-heat exchanger 132 by heat exchange with the heat source. At this time, the heating medium can maintain the liquid phase without phase change even after passing through the third heater 143.

As described above, the heating medium pump 151 is placed in the second heat exchanger 132 in a state in which the heating medium of the second circulation line L2 is maintained in the liquid state without being vaporized even if heated by the third heater 143 So that the heat medium supplied from the first suction drum 161 can be pressurized.

 The fourth heater 144 exchanges the heat medium with the heat source through the second heat exchanger 132 and the heat medium is stored in the second suction drum 162 in a liquefied state through the fourth heat exchanger 134.

The pressurizing pump 152 pressurizes the heating medium supplied from the second suction drum 162 and supplies it to the space between the heating medium pump 151 and the branch point D1 of the first circulation line L1.

 As described above, the liquefied gas regeneration system 100 performing the above-described process can improve regeneration efficiency and performance of the liquefied gas through heat exchange with the heating medium without using existing seawater.

In addition, the heating medium having different pressures and states are separately stored in the first suction drum 161 and the second suction drum 162 provided in the respective circulation lines L1 and L2, And L2 to reduce the electricity consumed by the pumps 151 and 152 on the respective circulation lines L1 and L2 and efficiently operate the liquefied gas regeneration system 100 .

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is clearly understood that the same is by way of illustration and example only and is not to be taken by way of limitation, You will understand. Accordingly, the true scope of the invention should be determined only by the appended claims.

100: liquefied gas regeneration system 110: storage tank
120: regasification line 121: first regasification line
122: second regasification line 123: delivery pump
124: supply pumps 131 to 134: first to fourth heat exchangers
140: Pressure reducing valves 141 to 144: First to fourth heaters
151: heating medium pump 152: pressure pump
L1: first circulation line L2: second circulation line

Claims (3)

A first regeneration line for allowing the liquefied gas supplied from the storage tank to be regenerated and heated by heat exchange with the heat medium sequentially through the first heat exchanger and the second heat exchanger and supplied to the customer;
A second regeneration line for allowing the liquefied gas to be regenerated and heated by heat exchange with the heat medium through the third heat exchanger and the fourth heat exchanger in sequence and to be supplied to the customer;
A first circulation line circulating the heat medium supplied from the first suction drum through the first heat exchanger and the third heat exchanger to the first suction drum; And
And a second portion of the first circulation line is branched from the rear end of the first suction drum of the first circulation line so that the divided portion of the heat medium supplied from the first suction drum is passed through the second heat exchanger and the fourth heat exchanger, And a second circulation line for joining the first suction drum and the branch point to each other and providing a second suction drum for storing the liquefied heat medium via the fourth heat exchanger,
Wherein the first suction drum stores a heating medium having a first pressure liquefied through the third heat exchanger and the second suction drum stores a heating medium having a second pressure higher than the first pressure, . The method according to claim 1,
Wherein the first circulation line is provided between the first suction drum and the merging point and includes a heating medium pump for pressurizing the heating medium supplied from the first suction drum,
A pressure reducing valve for reducing the pressure of the heat medium supplied to the first heat exchanger among the pressurized heat medium,
A first heater for heat-exchanging the decompressed heat medium with a heat source to send the decompressed heat medium to the first heat exchanger in a vaporized state,
And a second heater for exchanging heat with the heat source through the first heat exchanger and sending the heat medium to the third heat exchanger. 3. The method of claim 2,
The second circulation line includes a third heater for heat-exchanging the heat medium supplied to the second heat exchanger among the heat medium supplied from the first suction drum to the heat source,
A fourth heater for exchanging heat with the heat source through the second heat exchanger,
A pressurizing pump for pressurizing the heat medium supplied from the second suction drum is provided,
Wherein the heating medium pump pressurizes the heating medium supplied from the first suction drum in accordance with the set pressure so that the state of the heating medium passed through the third heater is maintained in a liquid state.

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