KR102239297B1 - Floating marine structure with electric power generator - Google Patents

Abstract

A floating offshore structure is disclosed. The floating offshore structure according to the present invention uses the steam generated by the waste heat recovery boiler of the power generation unit as a heat source of the heating unit that heats the vaporized LNG at room temperature and supplies it to the power generation unit. Then, since there is no need to separately provide a heat source of the heating unit for heating the vaporized LNG at room temperature, there may be an effect of reducing the cost. In addition, steam discharged from the heating unit is used as a heat source for vaporizing liquid LNG in the regasification unit. Then, since the temperature of the vaporized LNG is relatively high, the vaporized LNG can be heated with relatively little energy, or the vaporized LNG can be heated to a relatively high temperature. Therefore, there may be an effect of saving energy for heating the vaporized LNG. In addition, the seawater for condensing the steam of the condenser of the power generation unit is cooled by the cooling heat of the regasification unit and is then supplied to the condenser, so that the vapor of the condenser can be condensed with a relatively small amount of seawater. Therefore, there may be an effect of minimizing corrosion of pipelines by seawater.

Description

Floating offshore structure with power generation system {FLOATING MARINE STRUCTURE WITH ELECTRIC POWER GENERATOR}

The present invention relates to a floating offshore structure having a power generation system for heating LNG vaporized in a regasification unit using steam discharged from the power generation unit.

Today, as a part of interest in the environment, interest in eco-friendly power generation systems is increasing, and as a kind of eco-friendly power generation system, there is a power generation system that uses natural gas such as LNG (Liquefied Natural Gas) as power generation fuel.

However, in order to build a power generation system that uses natural gas as power generation fuel on land, infrastructure such as gas storage tanks and gas supply devices are required. It is difficult to build a power generation system.

In order to solve the above problems, a power generation system is installed on the hull equipped with a gas storage and gasification device, and after generating power from the hull, a floating offshore structure that transmits power to its own use and land use. Has been developed and used.

LNG used as power generation fuel is vaporized in the regasification unit and then burned to drive the gas turbine of the power generation system.

However, since the LNG vaporized in the regasification unit has a temperature of approximately room temperature, a lot of energy is required to burn the vaporized LNG at room temperature in the gas turbine. For this reason, before supplying the gasified LNG at room temperature to the gas turbine, it is preferable to heat it and then supply it to the gas turbine.

Conventional floating offshore structures use a separate heat source to heat the vaporized LNG at room temperature supplied to the gas turbine, so there is a disadvantage of increasing the cost.

Prior art related to the technology for power generation using LNG at sea is disclosed in Korean Patent Application Publication No. 10-2013-0108224 (October 02, 2013).

An object of the present invention may be to provide a floating offshore structure capable of solving all the problems of the prior art as described above.

Another object of the present invention may be to provide a floating offshore structure capable of reducing cost by heating the vaporized LNG at room temperature using steam discharged from the power generation unit and then supplying it to the gas turbine of the power generation unit.

The floating offshore structure according to this embodiment for achieving the above object includes: a hull; A storage tank installed on the hull and storing LNG (Liquefied Natural Gas); A regasification unit installed on the hull, receiving LNG from the storage tank and vaporizing it; A heating unit installed on the hull and heating the LNG vaporized in the regasification unit; Includes a power generation unit having a waste heat recovery boiler that is installed on the ship and generates power using LNG heated by the heating unit as power generation fuel, and generates steam using combustion gas generated during power generation, and heats the vaporized LNG. The heat source of the heating unit may include steam generated by the waste heat recovery boiler.

The floating offshore structure according to the present embodiment uses the steam generated by the waste heat recovery boiler of the power generation unit as a heat source of the heating unit that heats the vaporized LNG at room temperature and supplies it to the power generation unit. Then, since there is no need to separately provide a heat source of the heating unit for heating the vaporized LNG at room temperature, there may be an effect of reducing the cost.

In addition, steam discharged from the heating unit is used as a heat source for vaporizing liquid LNG in the regasification unit. Then, since the temperature of the vaporized LNG is relatively high, the vaporized LNG can be heated with relatively little energy, or the vaporized LNG can be heated to a relatively high temperature. Therefore, there may be an effect of saving energy for heating the vaporized LNG.

In addition, the seawater for condensing the steam of the condenser of the power generation unit is cooled by the cooling heat of the regasification unit and is then supplied to the condenser, so that the vapor of the condenser can be condensed with a relatively small amount of seawater. Therefore, there may be an effect of minimizing corrosion of pipelines by seawater.

1 is a view showing the configuration of a floating offshore structure according to a first embodiment of the present invention.
2 is a view showing the configuration of a floating offshore structure according to a second embodiment of the present invention.
3 is a view showing the configuration of a floating offshore structure according to a third embodiment of the present invention.

In the present specification, in adding reference numerals to elements of each drawing, it should be noted that, even though they are indicated on different drawings, the same elements are to have the same number as possible.

Meanwhile, the meaning of the terms described in the present specification should be understood as follows.

Singular expressions should be understood as including plural expressions unless clearly defined differently in context, and terms such as “first” and “second” are used to distinguish one element from other elements, The scope of rights should not be limited by these terms.

It is to be understood that terms such as "comprises" or "have" do not preclude the presence or addition of one or more other features, numbers, steps, actions, components, parts, or combinations thereof.

The term “at least one” is to be understood as including all possible combinations from one or more related items. For example, the meaning of “at least one of the first item, the second item, and the third item” is 2 of the first item, the second item, and the third item, as well as each It means a combination of all items that can be presented from more than one.

The term "and/or" is to be understood as including all possible combinations from one or more related items. For example, the meaning of “the first item, the second item and/or the third item” means two of the first item, the second item, or the third item as well as the first item, the second item, or the third item. It means a combination of all items that can be presented from the above.

When a component is referred to as being "connected or installed" to another component, it is to be understood that it may be directly connected or installed to the other component, but other components may exist in the middle. On the other hand, when a component is referred to as "directly connected or installed" to another component, it should be understood that the other component does not exist in the middle. On the other hand, other expressions describing the relationship between the constituent elements, that is, "between" and "directly between" or "adjacent to" and "directly adjacent to" should be interpreted as well.

Hereinafter, a floating offshore structure according to embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Embodiment 1

1 is a diagram showing the configuration of a floating offshore structure according to a first embodiment of the present invention.

As shown, the floating offshore structure according to the first embodiment of the present invention includes a hull 110, a storage tank 120, a regasification unit 130, a heating unit 140, a power generation unit 150, and a propulsion unit. It may include 180.

The hull 110 may float on the water surface by buoyancy, and the storage tank 120 may be installed on the hull 110 to store LNG (Liquefied Natural Gas). The storage tank 120 is preferably installed at the lower portion of the hull 110, and the LNG stored in the storage tank 120 is in a liquid state of about -160°C or less.

The regasification unit 130 is installed in the hull 110, and receives LNG from the storage tank 120 to vaporize the liquid LNG into a gaseous state, and the LNG vaporized in the regasification unit 130 is approximately room temperature ( It can have a temperature of 常溫). The regasification unit 130 may include a tank in which LNG is stored, a pump for discharging LNG from the tank, a carburetor for vaporizing LNG discharged from the tank, and the like.

The heating unit 140 may be installed on the hull 110 and may heat LNG at room temperature vaporized by the regasification unit 130 and supply it to the power generation unit 150. Since the vaporized LNG at room temperature is heated by the heating unit 140 and supplied to the power generation unit 150, the power generation unit 150 may burn the vaporized LNG using a relatively small amount of energy.

The power generation unit 150 may be installed on the hull 110 and may generate electricity by using the heated LNG supplied from the heating unit 140 as fuel.

The power generation unit 150 will be described.

The power generation unit 150 may include a gas turbine 151, a waste heat recovery boiler 153, a steam turbine 155, and a condenser 157.

The gas turbine 151 includes a compressor that compresses air, a combustor that receives high-pressure air from the compressor and injects and burns heated LNG, and a turbine that rotates by high-temperature/high-pressure combustion gases generated during combustion of LNG. I can. Thus, power is generated while the generator 151a is driven by the gas turbine 151.

The combustion gas driving the gas turbine 151 is discharged to the outside of the gas turbine 151, and the exhaust gas discharged from the gas turbine 151 may be introduced into the waste heat recovery boiler 153. The waste heat recovery boiler 153 generates steam by using the exhaust gas discharged from the gas turbine 151, and the steam generated from the waste heat recovery boiler 153 flows into the steam turbine 155 to feed the steam turbine 155. Drive.

Then, the generator 155a is generated while the generator 155a is driven by the steam turbine 155. The steam driving the steam turbine 155 is discharged and condensed in the condenser 157 to be discharged, and the condensed water condensed in the condenser 157 may be re-inflowed into the waste heat recovery boiler 153.

The floating offshore structure according to this embodiment drives the gas turbine 151 using combustion gas generated during combustion of vaporized LNG, and generates primary power while the generator 153a is driven by the gas turbine 151. . And, the waste heat recovery boiler 153 generates steam by using the exhaust gas discharged from the gas turbine 151, the steam turbine 155 is driven by the steam generated by the waste heat recovery boiler 153, and the steam turbine By 155, the generator 155a generates secondary power. Therefore, the power generation efficiency can be improved.

The floating offshore structure according to the present embodiment may use steam generated by the power generation unit 150 as a heat source of the heating unit 140 that heats the vaporized LNG at room temperature. More specifically, the vaporized LNG at room temperature may be heated by using the steam generated by the waste heat recovery boiler 153. Then, since there is no need to separately provide a heat source of the heating unit 140 for heating the vaporized LNG at room temperature, cost can be reduced.

In order to supply the steam generated by the waste heat recovery boiler 153 to the heating unit 140, there is a heating unit on one side of the steam supply pipe 161 for supplying steam from the waste heat recovery boiler 153 to the steam turbine 155 A steam supply branch pipe path 161a for supplying steam to 140 may be branched.

Steam from the steam supply branch pipe furnace 161a may be discharged from the heating unit 140 and introduced into the condenser 157 after heating the vaporized LNG introduced into the heating unit 140. In order to introduce the steam discharged from the heating unit 140 into the condenser 157 after passing through the heating unit 140, the steam supply branch pipe path 161a may extend to the condenser 157 side.

Reference numeral 180 in FIG. 1 is a propulsion unit for propelling the hull 110, and the propulsion unit 180 is a power device for rotating the propeller and a waste heat recovery boiler for recovering and generating waste heat generated from the power device. , A steam turbine and a condenser.

The floating offshore structure according to the first embodiment of the present invention is a waste heat recovery boiler of the power generation unit 150 as a heat source of the heating unit 140 that heats the vaporized LNG at room temperature and supplies it to the power generation unit 150. The steam generated in (153) is used. Then, since there is no need to separately provide a heat source of the heating unit 140 for heating the vaporized LNG at room temperature, cost can be reduced.

Embodiment 2

2 is a diagram showing the configuration of a floating offshore structure according to a second embodiment of the present invention, and only differences from the first embodiment will be described.

As shown, the floating offshore structure according to the second embodiment of the present invention may use steam discharged from the heating unit 240 as a heat source of the regasification unit 230 for vaporizing liquid LNG.

To this end, the first heat exchanger 263 exchanging heat with the steam discharged from the heating unit 240 and the heat exchange medium circulation pipe for supplying the heat exchange medium exchanged with the first heat exchanger 263 to the regasification unit 230 ( 264) may be further installed. Then, since the liquid LNG is vaporized in the regasification unit 230 by the heat of the vapor discharged from the relatively high temperature heating unit 240, the temperature of the vaporized LNG may be relatively high. Then, the heating unit 240 may heat the vaporized LNG using relatively little energy, or may heat the vaporized LNG to a relatively high temperature.

In order to heat the steam discharged from the heating unit 240 with the first heat exchanger 263, the steam supply branch pipe path 261a from the heating unit 240 to the condenser 257 is formed of the first heat exchanger 263. It can exchange heat with one side. In order to heat exchange the heat exchange medium with the first heat exchanger 263, one side of the heat exchange medium circulation pipe 264 may exchange heat with the other side of the first heat exchanger 263.

In the floating offshore structure according to the second embodiment of the present invention, since the temperature of the LNG vaporized in the regasification unit 240 is relatively high, it is possible to heat the vaporized LNG with relatively little energy, or to a relatively high temperature. Vaporized LNG can be heated. Therefore, it is possible to save energy for heating the vaporized LNG.

Embodiment 3

3 is a diagram showing the configuration of a floating offshore structure according to a third embodiment of the present invention, and only differences from the second embodiment will be described.

As shown, the floating offshore structure according to the third embodiment of the present invention may use seawater to condense the vapor of the condenser 357. The steam flowing into the condenser 357 and condensed is generated in the waste heat recovery boiler 353 to drive the steam turbine 355 and then discharged from the heating unit 340 and heat exchange with the first heat exchanger 363 It can be one steam.

Since the vapor of the condenser 357 is high temperature, a large amount of seawater is required to condense the vapor of the condenser 357. Then, a large number of pumps for pumping seawater are required, or a large-capacity pump is required, so that the cost may increase.

The floating offshore structure according to the third embodiment of the present invention uses the cold heat of the regasification unit 330 to condense the seawater supplied to the condenser 357 in order to condense the vapor of the condenser 357 with a relatively small amount of seawater. After cooling, it can be supplied to the condenser 357.

In order to cool the seawater supplied to the condenser 357 by the cold heat of the regasification unit 330, the heat exchange medium of the heat exchange medium circulation pipe path 364 heat-exchanged with the regasification unit 330 may be heat-exchanged with seawater.

In order to heat exchange the seawater and the heat exchange medium, a second heat exchanger 366 and a seawater supply pipe 368 may be provided. One side of the second heat exchanger 366 exchanges heat with a portion of the heat exchange medium circulation pipe 364 through which the heat exchange medium heat-exchanged with the regasification unit 330 passes, and the other side is the front end of the seawater supply pipe 368 through which seawater flows. It can exchange heat with the negative side.

Then, the seawater of the seawater supply pipe 368 is cooled by heat exchange with the second heat exchanger 366 and then supplied to the condenser 357, so that the vapor of the condenser 357 can be condensed with a relatively small amount of seawater. . For this reason, it is possible to minimize the corrosion of pipes by seawater.

Some of the seawater discharged from the condenser 357 may be re-inflowed into the condenser 357. To this end, in the seawater supply pipe 368, a seawater supply branch pipe passage 368a for re-introducing the seawater discharged from the condenser 357 into the condenser 357 may be branched. One side of the seawater supply branch pipe line 368a communicates with the rear end side of the seawater supply pipe line 368 that has passed through the condenser 357, and the other side is the front end of the seawater supply pipe line 368. ) Can communicate with the side. Since seawater that is joined from the seawater supply branch pipe path 368a to the seawater supply pipe path 368 must be re-inflowed to the condenser 357 after reheat exchange with the second heat exchanger 366, the other It is natural that the side should communicate with the portion of the seawater supply pipe 368 between the front end of the seawater supply pipe 368 and the second heat exchanger 366.

In the floating offshore structure according to the third embodiment of the present invention, after the seawater for condensing the vapor of the condenser 357 is cooled by the cold heat of the regasification unit 330, it is supplied to the condenser 357, so relatively little The vapor of the condenser 357 can be condensed with positive seawater. Therefore, it is possible to minimize the corrosion of pipes by seawater.

The present invention described above is not limited to the above-described embodiments and the accompanying drawings, and various substitutions, modifications and changes are possible within the scope of the technical spirit of the present invention. It will be obvious to those who have the knowledge of. Therefore, the scope of the present invention is indicated by the claims to be described later, and all changes or modifications derived from the meaning and scope of the claims and their equivalent concepts should be interpreted as being included in the scope of the present invention.

110: hull
120: storage tank
130: regasification unit
140: development department

Claims (8)

hull;
A storage tank installed on the hull and storing LNG (Liquefied Natural Gas);
A regasification unit installed on the hull, receiving LNG from the storage tank and vaporizing it;
A heating unit installed on the hull and heating the LNG vaporized in the regasification unit;
It includes a power generation unit having a waste heat recovery boiler that is installed in the hull and generates steam using the LNG heated by the heating unit as power generation fuel, and generates steam using combustion gas generated during power generation,
The heat source of the heating unit for heating the vaporized LNG includes steam generated in the waste heat recovery boiler,
The steam discharged from the heating unit and a heat exchange medium supplied to the regasification unit further include a first heat exchanger for exchanging heat with each other,
The first heat exchanger,
The vapor discharged after heating LNG in the heating unit is used as a heat source for heating the heat exchange medium supplied to the regasification unit, and liquid LNG is discharged from the regasification unit by the heat of the steam discharged from the heating unit. Floating offshore structure characterized in that to be vaporized. delete The method of claim 1,
A floating offshore structure further comprising a condenser in which steam discharged from the heating unit and used as a heat source of the regasification unit is condensed through heat exchange with seawater. The method of claim 3,
The seawater supplied to the condenser is cooled by the cooling heat of the regasification unit and then supplied to the condenser. delete The method of claim 1,
A floating offshore structure further comprising a condenser in which the steam discharged after heat exchange with the heat exchange medium in the first heat exchanger is condensed through heat exchange with seawater. The method of claim 6,
A floating offshore structure further comprising a heat exchange medium discharged after heat exchange with LNG in the regasification unit, and a second heat exchanger for heat exchange with seawater supplied to the condenser. The method of claim 7,
A floating offshore structure configured to be re-supplied to the condenser after at least part of the seawater discharged from the condenser is reheat exchanged with the heat exchange medium in the second heat exchanger.

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