KR20190030988A - Boil-Off-Gas Processing system and BOG Processing method in Floating Gas Power Plant - Google Patents

Abstract

Provided is a boil-off-gas (BOG) treatment system in a floating type gas power plant according to an embodiment of the present invention. The boil-off-gas treatment system in a floating type gas power plant according to an embodiment of the present invention includes: at least one liquefied gas storage tank for storing liquefied gas therein; a power unit for receiving at least one among natural BOG (nBOG) generated by natural vaporization of the liquefied gas stored in the liquefied gas storage tank and forced BOG (fBOG) generated by forced vaporization of the liquefied gas stored in the liquefied gas storage tank; and a reliquefaction unit operated by receiving electric power from the power unit and reliquefying the natural BOG to supply the reliquefied natural BOG to the liquefied gas storage tank. The remaining natural BOG generated in the liquefied gas storage tank, which is not supplied to the power unit, is stored in the liquefied gas storage tank to maintain internal pressure of the liquefied gas storage tank within an allowable range, and the remainder excessing the allowable range of the liquefied gas storage tank may be supplied to the reliquefaction unit.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a boil-off gas processing system and a floating gas power plant,

The present invention relates to an evaporative gas treatment system and an evaporative gas treatment method for a floating gas power plant, and more particularly, to an evaporative gas treatment system for a floating gas power plant capable of efficiently treating evaporative gas And a method of treating the evaporative gas.

Floating gas power plants (FGPPs) typically float on the sea and produce power and represent offshore structures that supply the generated power to offshore or offshore plants. Floating gas power plants are operated in coastal waters where environmental regulations are strongly enforced due to cost increase due to the use of electric power supply cables and power loss. As a result, liquefied gas It is used as fuel for power generation. Although liquefied gas is environmentally friendly, it is easily evaporated even when the temperature is slightly increased, thereby causing boil-off-gas (BOG).

Conventionally, the evaporation gas generated is stored in a storage tank or is re-liquefied and then stored in a storage tank. However, the capacity for storing the evaporation gas in the storage tank and the capacity for treating the evaporation gas in the refueling apparatus are limited, and a separate apparatus for treating the surplus evaporation gas is required. Accordingly, although the surplus evaporation gas is incinerated using the incinerator, there is a problem that the cost of using the incinerator is increased and the utilization of the space in the plant is lowered. In particular, since the surplus evaporated gas is burned away, the processing of the evaporated gas is not efficiently performed.

Korean Patent No. 10-0875064 (December 12, 2008)

SUMMARY OF THE INVENTION It is an object of the present invention to provide an evaporative gas treatment system for a floating gas power plant capable of efficiently treating evaporative gas in accordance with the amount of generated electricity.

It is another object of the present invention to provide a method of treating an evaporative gas of a floating gas power plant capable of efficiently processing evaporative gas in accordance with an amount of generated electricity.

The technical objects of the present invention are not limited to the technical matters mentioned above, and other technical subjects not mentioned can be clearly understood by those skilled in the art from the following description.

According to an aspect of the present invention, there is provided an evaporative gas treatment system for a floating gas power plant, comprising: at least one liquefied gas storage tank for storing a liquefied gas therein; At least one of a natural evaporation gas (nBOG) generated by natural gasification of a liquefied gas and a forced evaporative gas (fBOG) generated by forcibly vaporizing the liquefied gas stored in the liquefied gas storage tank is supplied as fuel gas to produce electric power And a liquefaction unit for supplying power to the liquefied gas storage tank by re-liquefying the natural evaporation gas while being supplied with power from the power generation unit, wherein the natural evaporation gas generated from the liquefied gas storage tank The remaining amount of the total generated gas supplied to the power generation unit is stored in the liquefied gas storage tank, The rest of maintaining the internal pressure of the tank within the allowable range and, out of range of the liquefied gas storage tank is supplied to the re-liquefaction unit.

The evaporative gas treatment system of the floating gas power plant includes a sensor unit for measuring an internal pressure of the liquefied gas storage tank, and a controller for controlling the natural evaporation gas to the liquefied gas storage tank And to be supplied to the re-liquefaction unit.

The evaporative gas treatment system of the floating gas power plant includes an evaporative gas supply line for supplying the natural evaporative gas inside the liquefied gas storage tank to the power generation unit, And a compression unit for compressing the input signal.

The evaporative gas treatment system of the floating gas power plant may further include a first evaporative gas supply line branched from the evaporative gas supply line at the upstream end of the compression unit and connected to the refill liquefaction unit.

The evaporative gas treatment system of the floating gas power plant may further include a second evaporative gas supply line branched from the evaporative gas supply line at the downstream end of the compression unit and connected to the refill liquefaction unit.

Wherein the evaporative gas supply line of the floating gas generating plant is connected to the power generation unit by the natural evaporation gas at a pressure lower than the pressure of the natural evaporative gas branched from the compression unit by the evaporative gas supply line, And a third evaporation gas supply line for supplying the natural evaporation gas discharged from the compression unit to the re-liquefaction unit.

According to another aspect of the present invention, there is provided a method for treating an evaporative gas in a floating gas power plant, comprising the steps of: supplying at least one natural evaporation gas generated by natural vaporization of a liquefied gas in at least one liquefied gas storage tank, (A) supplying power to the power generation unit with fuel gas; and storing the remaining natural vaporized gas supplied to the power generation unit in the liquefied gas storage tank to supply the internal pressure to the liquefied gas storage tank (C) of supplying the remainder of the natural vaporizing gas to the re-liquefaction unit and re-liquefying the natural evaporation gas in excess of the allowable range of the liquefied gas storage tank, (D) to the liquefied gas storage tank, wherein, in response to the amount of the fuel gas required in the power generating unit, The amount of the natural evaporation gas re-liquefied in the flash unit is varied.

The step (A) may include supplying at least one of the natural evaporation gas and the forced evaporation gas generated by forcibly vaporizing the liquefied gas stored in the liquefied gas storage tank to the power generation unit.

(B-1) of measuring the internal pressure of the liquefied gas storage tank after the step (B), and a step (B-1) of measuring the internal pressure of the liquefied gas storage tank after the step (B) (B-2) controlling the natural evaporation gas to be stored in the liquefied gas storage tank or supplied to the liquefaction unit in response to the pressure value.

The method for treating an evaporative gas in the floating gas power plant may further include a step (C-0) of supplying power generated in the power generation unit to the remanufacturing unit before the step (C).

Wherein the compression unit installed on an evaporation gas supply line connecting the liquefied gas storage tank and the power generation unit compresses the natural evaporation gas and supplies the natural evaporation gas to the power generation unit, (C-1) in which the natural evaporation gas of the negative shear is supplied to the remelting unit through the first evaporation gas supply line.

Wherein the compression unit installed on an evaporation gas supply line connecting the liquefied gas storage tank and the power generation unit compresses the natural evaporation gas and supplies the natural evaporation gas to the power generation unit, (C-1 ') in which the natural evaporation gas at the downstream end is supplied to the remelting unit through the second evaporation gas supply line.

The method for treating an evaporative gas in a floating gas power plant according to claim 1, wherein a compression unit installed on an evaporative gas supply line connecting the liquefied gas storage tank and the electric power generation unit compresses the natural evaporative gas to supply the evaporative gas to the electric power generation unit, The gas supply line supplies the natural evaporation gas to the power generation unit at a pressure lower than the pressure of the natural evaporation gas branched from the compression unit and discharged from the compression unit, (C-1 ") supplied to the redistribution unit through the third evaporation gas supply line.

According to the present invention, the evaporation gas can be efficiently treated in accordance with the amount of power generation of the power generation plant and the amount of generation of the evaporation gas. Therefore, the fuel supply to the power generation unit and the pressure maintenance inside the liquefied gas storage tank can be facilitated, thereby improving the power generation efficiency of the plant.

1 is a block diagram schematically illustrating an evaporative gas treatment system of a floating gas power plant according to an embodiment of the present invention.
2 is a flowchart schematically showing a method of treating the evaporative gas of a floating gas power plant.
3 is an operational view for explaining the operation of the evaporative gas treatment system of the floating gas power plant.
4 is a block diagram schematically illustrating an evaporative gas treatment system of a floating gas power plant according to another embodiment of the present invention.
5 is a block diagram schematically illustrating an evaporative gas treatment system of a floating gas power plant according to another embodiment of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS The advantages and features of the present invention, and the manner of achieving them, will be apparent from and elucidated with reference to the embodiments described hereinafter in conjunction with the accompanying drawings. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. To fully disclose the scope of the invention to those skilled in the art, and the invention is only defined by the scope of the claims. Like reference numerals refer to like elements throughout the specification.

Hereinafter, with reference to Figs. 1 to 3, the evaporative gas treatment system and the evaporative gas treatment method of the floating gas power plant according to one embodiment of the present invention will be described in detail.

The evaporative gas treatment system of the floating gas power plant according to an embodiment of the present invention is for treating the natural evaporation gas generated by spontaneously vaporizing the liquefied gas stored in the liquefied gas storage tank, The evaporation gas can be efficiently treated in accordance with the amount of the generated gas. Therefore, the fuel supply to the power generation unit and the pressure maintenance inside the liquefied gas storage tank can be easily performed, thereby improving the power generation efficiency of the plant.

Hereinafter, the evaporative gas treatment system and the evaporative gas treatment method of the floating gas power plant will be described in detail with reference to Figs. 1 and 2. Fig.

FIG. 1 is a block diagram schematically showing an evaporative gas treatment system of a floating gas power plant according to an embodiment of the present invention, and FIG. 2 is a flow chart schematically showing a method of treating an evaporative gas of a floating gas power plant .

An evaporative gas treatment system (1) of a floating gas power plant according to the present invention includes a liquefied gas storage tank (10), a power generation unit (20), and a remelting unit (30).

The liquefied gas storage tank 10 is a tank for storing liquefied gas therein, and at least one tank may be formed inside the floating gas power plant 100. Here, the liquefied gas is a gas obtained by liquefying or liquefying a compound or mixture in a gaseous state, for example, a liquefied natural gas (LNG) or a liquefied petroleum gas (LNG) LPG). A plurality of liquefied gas storage tanks 10 may be spaced apart from each other and may be, for example, pressure type B-type tanks of the International Maritime Organization (IMO). The pressure type B-type tank is a membrane tank, and the operating pressure is rather low. However, since the volume of the storage tank is large, the natural vaporized gas produced by the liquefied gas is not discharged to the outside, . In other words, the increase in pressure and temperature due to the storage of the natural vaporized gas can be tolerated within acceptable limits. However, the liquefied gas storage tank 10 is not limited to being formed as a pressure type B-type tank, and may be modified into various kinds of pressure type tanks.

The natural vaporized gas in the liquefied gas storage tank 10 is supplied to the power generation unit 20.

The power generation unit 20 includes a natural evaporation gas nBOG generated by spontaneously vaporizing the liquefied gas stored in the liquefied gas storage tank 10 and a forced evaporation generated by forcibly vaporizing the liquefied gas stored in the liquefied gas storage tank 10 Gas (fBOG) as fuel gas to produce electric power, for example, a main engine, a generator, a boiler, or the like. That is, when the amount of the natural evaporation gas generated in the liquefied gas storage tank 10 is large, the power generation unit 20 generates only the natural evaporation gas and generates electric power. When the amount of the natural evaporation gas generated is small, 20) can supply both natural and forced evaporation gas at the same time.

The natural evaporation gas is supplied to the power generation unit 20 through the evaporation gas supply line 40 connecting the inside of the liquefied gas storage tank 10 and in particular the upper portion thereof with the power generation unit 20 and the forced evaporation gas is stored in the liquefied gas storage Can be supplied to the power generating unit 20 through the liquefied gas supply line 50 connecting the power generating unit 20 and the inside of the tank 10,

The evaporation gas supply line 40 is connected to the upper portion of each liquefied gas storage tank 10 and is joined to the power generation unit 20 and connected to the liquefied gas storage tank 10 at one side close to the liquefied gas storage tank 10, A control valve for controlling the flow of the natural evaporative gas discharged from the tank 10 may be provided. At least one compression unit 40a and a cooler 70 are provided on the evaporation gas supply line 40 so as to compress and cool the natural evaporation gas at the pressure and temperature required by the power generation unit 20 and supply the natural evaporation gas. The compression section 40a and the cooler 70 may be disposed in front of the power generation unit 20.

The liquefied gas supply line 50 is connected to the pump 50a provided below each liquefied gas storage tank 10 and joined to the power generation unit 20 or the evaporation gas supply line 40, A control valve for controlling the flow of the liquefied gas discharged from each of the liquefied gas storage tanks 10 may be provided on one side close to the tank 10. [ At least one heating unit 50b is provided on the liquefied gas supply line 50 to generate a forced evaporation gas by forcibly vaporizing the liquefied gas and the power generation unit 20 or the evaporation gas A control valve may be provided to control the flow of the forced evaporation gas to the supply line 40. When the liquefied gas supply line 50 is connected to the evaporation gas supply line 40, since the liquefied gas is pressurized in the pump 50a and then vaporized in the heating unit 50b, the liquefied gas supply line 50 May be connected to the downstream end of the cooler (70).

The power produced by the power generation unit 20 can be supplied to at least one of the first power consumption unit 21 and the second power consumption unit 22. [

The first power consumption unit 21 is a variety of equipment for operation of the floating gas power plant 100. The first power consumption unit 21 is a device for operating the floating gas power plant 100, It can be always driven by receiving power even during the power generation period. The second power consumption unit 22 is a device for supplying electric power to an onshore or offshore plant. The second power consumption unit 22 can be driven by supplying power only during a power generation period. The amount of fuel gas required in the power generation unit 20 is reduced during the power generation period in which the first power consumption unit 21 and the second power consumption unit 22 operate simultaneously, The amount of the fuel gas may be increased.

On the other hand, a part of the natural evaporation gas may be supplied to the re-liquefaction unit 30. [ The re-liquefier unit 30 re-liquefies the natural vaporized gas and supplies it to the liquefied gas storage tank 10, which can be powered by the power generation unit 20 and driven. The natural evaporation gas is supplied to the refueling unit 30 through the first evaporation gas supply line 41 branched from the evaporation gas supply line 40 at the upstream end of the compression section 40a and connected to the refueling unit 30 And a control valve for controlling the flow of the natural evaporation gas may be provided on the first evaporation gas supply line 41. The first evaporation gas supply line 41 is opened when a larger amount of natural evaporation gas than the amount of fuel gas required in the power generation unit 20 is generated and the natural evaporation gas in the pre- Can supply. The re-liquefier unit 30 re-liquefies the natural evaporation gas in a conventional manner that compresses the natural evaporation gas and then cools it by heat exchange with the refrigerant, and supplies the re-liquefied evaporation gas, that is, the liquefied gas to the liquefied gas storage tank 10 . At this time, the liquefied gas discharged from the liquefaction unit 30 can be supplied to the liquefied gas storage tank 10 through the loading line 60 for loading the liquefied gas. The loading line 60 is branched to each liquefied gas storage tank 10 and a control valve may be provided to control the flow of the liquefied gas.

An amount corresponding to a part of the total generation amount of the natural evaporated gas generated in the liquefied gas storage tank 10, specifically, an amount required in the power generation unit 20 is supplied to the power generation unit 20, The remaining supplied and remained can be stored in the liquefied gas storage tank 10 without being discharged to the outside to maintain the internal pressure of the liquefied gas storage tank 10 within the allowable range. At this time, when the natural evaporation gas is generated from each of the plurality of liquefied gas storage tanks 10, the natural evaporation gas can be stored in each of the liquefied gas storage tanks 10, The natural vaporized gas can be stored in any one of the liquefied gas storage tanks 10. [ The internal pressure of the liquefied gas storage tank 10 is reduced as the natural evaporation gas in the liquefied gas storage tank 10 is supplied to the power generation unit 20 and when the internal pressure is continuously decreased, Supply may not be smooth. The remaining natural evaporation gas supplied to the power generation unit 20 is stored in the liquefied gas storage tank 10 without being discharged to the outside so that the surplus natural evaporation gas can be processed without consuming any additional energy, The internal pressure of the tank 10 can be kept within an allowable range. Therefore, the supply of the fuel gas to the power generation unit 20 can be smoothly performed, and the separate pump device for supplying the natural vaporized gas to the power generation unit 20 can be omitted, Can be increased.

Meanwhile, the size of the space required for storing the natural vaporized gas in the liquefied gas storage tank 10 may vary depending on the amount of the natural evaporation gas, the ambient temperature, the power generation period, and the allowable tank pressure. For example, when the outside air temperature is high, the amount of heat that flows into the liquefied gas storage tank 10 increases, and the amount of the natural evaporation gas is increased. As the amount of the natural evaporation gas is increased, . In addition, since the amount of the natural evaporation gas consumed in the power generation unit 20 increases during the power generation period, the required storage space can be reduced. Further, the larger the pressure of the allowable tank, the larger the amount of natural evaporation gas can be stored, so that the required storage space can be reduced in size. The size of the space required for the storage of the natural evaporation gas is varied, and accordingly, the maximum water level of the liquefied gas storage tank 10 can also be varied.

As described above, since the liquefied gas storage tank 10 is a pressure type tank, the permissible internal pressure is limited. In other words, since the amount of natural evaporation gas that can be stored in the liquefied gas storage tank 10 is determined, the remaining natural evaporation gas exceeding the allowable pressure range of the liquefied gas storage tank 10 is supplied to the re-liquefaction unit 30 . The remaining natural evaporation gas supplied to the power generation unit 20 is stored in the liquefied gas storage tank 10 and the remaining natural evaporation gas stored in the liquefied gas storage tank 10 is supplied to the refueling unit 30 The energy required for re-liquefying the natural evaporation gas can be reduced, and even if the capacity of the re-liquefaction unit 30 is small, the natural evaporation gas can be easily treated. That is, the capacity of the re-liquefier unit 30 can be reduced, resulting in cost reduction and space utilization.

Each of the liquefied gas storage tanks 10 is provided at its one side with a sensor unit 80 for measuring the internal pressure and the measured pressure value from the sensor unit 80 can be transmitted to the controller 90. The control unit 90 can control the natural evaporation gas to be stored in the liquefied gas storage tank 10 or supplied to the remelting unit 30 in correspondence with the measured pressure value. For example, when the pressure value measured by the sensor unit 80 is less than the allowable range of the liquefied gas storage tank 10, the control unit 90 can continuously store the natural vaporized gas in the liquefied gas storage tank 10 have. On the contrary, when the pressure value measured by the sensor unit 80 exceeds the allowable range of the liquefied gas storage tank 10, the control unit 90 stops storing the natural vaporized gas in the liquefied gas storage tank 10 At the same time, the natural evaporation gas can be supplied to the re-liquefaction unit (30). The control unit 90 controls the operation of each control valve provided on the evaporation gas supply line 40, the liquefied gas supply line 50, the loading line 60 and the first evaporation gas supply line 41 .

Meanwhile, during the non-power generation period, the power generation unit 20 needs to produce only the minimum power required for operation of the floating gas power plant 100 and the power required to drive the re-liquefaction unit 30, The amount is reduced. In this case, the remaining natural vaporized gas supplied to the power generation unit 20 may be stored in each of the plurality of liquefied gas storage tanks 10, The natural evaporation gas may be supplied to the refueling unit 30 and re-liquefied. That is, in the non-power generation period, the amount of the natural evaporation gas re-liquefied in the re-liquefier unit 30 relatively increases, and the amount of the natural evaporation gas re-liquefied in the re-liquefier unit 30 in the power generation period is relatively decreased . The evaporated gas stored in the liquefied gas storage tank 10 may be supplied to the power generation unit 20 and used as the fuel gas.

The method for treating an evaporative gas in a floating gas power plant according to the present invention includes the steps of (A) supplying a natural evaporation gas to a power generation unit (20) to produce electric power, (C) storing the remaining natural evaporation gas stored in the liquefied gas storage tank (10) to the re-liquefaction unit (30); and (B) (D) of supplying the natural evaporated gas to the liquefied gas storage tank 10, wherein the amount of the fuel gas required in the power generation unit 20 corresponds to the liquefied natural gas The amount of gas can vary.

(B-1) measuring the internal pressure of the liquefied gas storage tank 10, and a step (B-1) of causing the sensor unit 80 to measure the internal pressure of the liquefied gas storage tank 10, (B-2) of storing the gas in the gas storage tank 10 or supplying it to the re-liquefaction unit 30, (C-0) supplying the power generated by the power generation unit 20 to the re- (C-1) of supplying the natural evaporation gas at the upstream end of the compression section 40a to the liquefaction unit 30.

In the at least one liquefied gas storage tank 10 storing the liquefied gas therein, the liquefied gas is spontaneously vaporized to generate a natural vaporized gas. The generated natural vaporized gas is supplied to the liquefied gas storage tank 10 and the power generation unit 20, To the power generation unit 20 via the evaporation gas supply line 40 connecting the evaporation gas supply line 40 and the evaporation gas supply line 40. At this time, a compression unit 40a and a cooler 70 are installed on the evaporation gas supply line 40 to compress and cool the natural evaporation gas to the pressure and temperature required by the power generation unit 20, and supply the natural evaporation gas. The power generation unit 20 supplies the natural evaporation gas to the fuel gas to produce electric power (step (A)), and supplies the generated electric power to at least one of the first power consumption unit 21 and the second power consumption unit 22 . The first power consumption unit 21 is always driven not only in the power generation period but also in the non-power generation period for the operation of the floating gas power plant 100, and the second power consumption unit 22 can be driven only during the power generation period. That is, in the power generation period, the power generated in the power generation unit 20 is supplied to the first power consumption unit 21 and the second power consumption unit 22, respectively. In the non-power generation period, (21).

On the other hand, when the natural evaporation gas generated in the liquefied gas storage tank 10 is smaller than the amount required in the power generation unit 20, the natural evaporation gas and the liquefied gas stored in the liquefied gas storage tank 10 are forcedly vaporized And at least one of the generated forced evaporation gases may be supplied to the power generation unit 20. The forced evaporation gas is generated as the liquefied gas passes through the heating section 50b provided on the liquefied gas supply line 50 and is joined to the evaporation gas supply line 40 at the rear end of the cooler 70 to be supplied to the power generation unit 20, As shown in FIG.

The remaining natural evaporation gas supplied to the power generation unit 20 may be stored in the liquefied gas storage tank 10 to maintain the pressure inside the liquefied gas storage tank 10 within the allowable range (step (B)). The internal pressure of the liquefied gas storage tank 10 gradually decreases as the natural vaporized gas in the liquefied gas storage tank 10 is supplied to the power generation unit 20, Supply may not be smooth. The remaining natural vaporized gas supplied to the power generation unit 20 is stored in the liquefied gas storage tank 10 so that the internal pressure of the liquefied gas storage tank 10 is maintained within the allowable range so that the supply of the fuel gas can be smoothly performed have. When the natural evaporation gas is stored in the liquefied gas storage tank 10, the sensor unit 80 measures the internal pressure of the liquefied gas storage tank 10 (step (B-1)), It is possible to control the natural evaporation gas to be stored in the liquefied gas storage tank 10 or supplied to the remelting unit 30 (step (B-2)) in correspondence with the pressure value measured at the unit 80.

When the pressure value measured by the sensor unit 80 is lower than the allowable range of the liquefied gas storage tank 10, the controller 90 can continuously store the natural vaporized gas in the liquefied gas storage tank 10. Conversely, when the pressure value measured by the sensor unit 80 exceeds the allowable range of the liquefied gas storage tank 10, the control unit 90 stops storing the natural vaporized gas in the liquefied gas storage tank 10, The remaining natural evaporation gas can be supplied to the re-liquefaction unit 30 to be re-liquefied (step (C)). The power produced by the power generation unit 20 can be supplied to the remelting unit 30 in advance (step (C-0)) before the natural evaporation gas is supplied to the re-liquefaction unit 30. [

The natural evaporation gas is supplied to the refueling unit 30 through the first evaporation gas supply line 41 branched from the evaporation gas supply line 40 at the upstream end of the compression section 40a and connected to the refueling unit 30 (Step (C-1)), the re-liquefier unit 30 can compress the natural evaporation gas, cool it, and re-liquefy it. The amount of the natural evaporation gas re-liquefied in the re-liquefying unit 30 can be varied corresponding to the amount of the fuel gas required in the power generation unit 20. [ For example, since the amount of the fuel gas consumed by the power generation unit 20 increases during the power generation period, the amount of the natural vaporized gas re-liquefied in the re-liquefying unit 30 decreases, The amount of the natural evaporation gas re-liquefied in the re-liquefier unit 30 can be increased.

The liquefied natural vaporizing gas, that is, the liquefied gas in the liquefaction unit 30 can be supplied to the liquefied gas storage tank 10 through the loading line 60 (step (D)).

Hereinafter, with reference to FIG. 3, the process of operating the evaporative gas treatment system of the floating gas power plant will be described in more detail.

3 is an operational view for explaining the operation of the evaporative gas treatment system of the floating gas power plant.

The evaporative gas treatment system 1 of the floating gas power plant according to the embodiment of the present invention can efficiently treat the evaporative gas corresponding to the power generation amount of the power generation plant and the generation amount of the evaporative gas. Therefore, the fuel supply to the power generation unit 20 and the pressure maintenance inside the liquefied gas storage tank 10 can be facilitated, thereby improving the power generation efficiency of the plant.

3 (a) is a view showing a process of treating an evaporated gas when the amount of natural evaporation gas generated in the liquefied gas storage tank is sufficient during the power generation period, and FIG. 3 (b) FIG. 2 is a view showing a process of evaporating a gas in a case where the amount of natural evaporation gas generated in the evaporator is insufficient.

3 (a), the natural evaporation gas generated by spontaneously vaporizing the liquefied gas in each of the liquefied gas storage tanks 10 is supplied to the compression unit 40a through the evaporation gas supply line 40, And the cooler 70, and then supplied to the power generation unit 20. The power generation unit 20 supplies the natural evaporation gas to the fuel gas to produce electric power, and supplies the produced electric power to the first power consumption unit 21 and the second power consumption unit 22, respectively.

The remaining natural evaporation gas supplied to the power generation unit 20 and remaining can be stored in each of the liquefied gas storage tanks 10. As the natural vaporized gas is stored in the liquefied gas storage tank 10, the internal pressure of the liquefied gas storage tank 10 is maintained within the allowable range, so that the fuel gas supply to the power generation unit 20 can be smoothly performed. At this time, the sensor unit 80 measures the internal pressure of the liquefied gas storage tank 10 in real time, and the controller 90 controls the flow of the natural evaporation gas in accordance with the measured value of the sensor unit 80 .

When the pressure value measured by the sensor unit 80 exceeds the allowable range of the liquefied gas storage tank 10, the storage of the natural vaporized gas in the liquefied gas storage tank 10 is stopped, Liquefier unit 30, and supplies the natural evaporation gas to the re-liquefier unit 30. [0050] At this time, the natural evaporation gas is supplied to the re-liquefaction unit 30 through the first evaporation gas supply line 41 branched from the front end of the compression unit 40a, The liquefied natural vaporized gas is stored in the liquefied gas storage tank 10 through the loading line 60. [

On the other hand, in the non-power generation period, power supply to the second power consumption unit 22 is restricted. That is, since the amount of the fuel gas consumed in the power generation unit 20 is reduced, the number of the liquefied gas storage tanks 10 necessary for storing the natural evaporation gas can be increased. The remaining natural vapor gas stored in the liquefied gas storage tank 10 can be re-liquefied in the liquefaction unit 30. [

3 (b), the natural evaporation gas generated in each of the liquefied gas storage tanks 10 flows through the evaporation gas supply line 40 through the compression unit 40a and the cooler 70 And is supplied to the post-generation unit 20. At this time, when the amount of the natural evaporation gas is insufficient, the power generation unit 20 can simultaneously supply the natural evaporative gas and the forced evaporative gas to produce electric power. The forced evaporation gas is supplied to the power generation unit 20 through the liquefied gas supply line 50 and the liquefied gas supply line 50 is used to forcibly supply the liquefied gas stored in the liquefied gas storage tank 10 from the heating unit 50b And vaporizes to generate forced evaporation gas. The power generation unit 20 supplies the produced power to the first power consumption unit 21 and the second power consumption unit 22, and the remelting unit 30 is not driven.

On the other hand, during the non-power generation period, the amount of the fuel gas consumed in the power generation unit 20 decreases, so that it can be covered only with the natural evaporation gas or mixed with the forced evaporation gas as necessary.

Hereinafter, with reference to Fig. 4, the evaporative gas treatment system 1 of the floating gas power plant according to another embodiment of the present invention will be described in detail.

4 is a block diagram schematically illustrating an evaporative gas treatment system of a floating gas power plant according to another embodiment of the present invention.

The evaporation gas processing system 1 of the floating gas power plant according to another embodiment of the present invention is branched from the evaporation gas supply line 40 at the downstream end of the compression section 40a instead of the first evaporation gas supply line 41, And a second evaporation gas supply line (42) connected to the liquefaction unit (30). The evaporation gas processing system 1 of the floating gas power plant according to another embodiment of the present invention is branched from the evaporation gas supply line 40 at the downstream end of the compression section 40a instead of the first evaporation gas supply line 41, And the second evaporation gas supply line 42 connected to the liquefaction unit 30. The second evaporation gas supply line 42 is connected to the liquefaction unit 30, Therefore, the description will be focused on, but unless otherwise noted, the description of the remaining components is replaced by the foregoing.

The remaining natural evaporation gas supplied to the power generation unit 20 and remaining can be supplied to the remelting unit 30. [ At this time, the natural evaporation gas is branched at the downstream end of the compression section 40a, more specifically, at the evaporation gas supply line 40 at the downstream end of the cooler 70, to be connected to the re-liquefier 31 of the re- And a control valve for controlling the flow of the natural evaporation gas may be provided on the second evaporation gas supply line 42 through the evaporation gas supply line 42. The operation of the control valve can be controlled by the control unit (90). The second evaporation gas supply line 42 is opened when a larger amount of natural evaporation gas than the amount of fuel gas required in the power generation unit 20 is generated and is compressed in the compression section 40a and cooled in the cooler 70 It is possible to supply a part of the natural evaporation gas to the re-liquefaction unit 30. When the natural evaporation gas is supplied to the re-liquefaction unit 30 through the second evaporation gas supply line 42, the compression unit 40a is designed to compress the total amount of the natural evaporation gas generated during the power generation period . The compressed and cooled natural evaporation gas is supplied to the re-liquefaction unit 30, so that it is not necessary to provide a separate compressor in the re-liquefaction unit 30, so that the cost can be reduced and the space utilization can be increased. However, the present invention is not limited to the case where the re-liquefier unit 30 is not provided with a separate compressor, If the pressure is high, a separate compressor may be additionally provided.

The method of treating the evaporative gas of the floating gas power plant may further include a step of supplying the natural evaporation gas at the downstream end of the compression unit 40a to the liquefaction unit 30, (C-1 ') of supplying the re-liquefier unit 30 with the re-liquefier unit 30.

The natural evaporation gas is supplied to the refueling unit 30 through the second evaporation gas supply line 42 branched from the evaporation gas supply line 40 at the downstream end of the compression section 40a and connected to the refueling unit 30 (Step (C-1 ')), the re-liquidifier 31 of the re-liquefier unit 30 is compressed and cooled to further cool the supplied natural evaporation gas to re-liquefy it. Since the natural evaporation gas supplied to the re-liquidator 31 through the second evaporation gas supply line 42 is first cooled by the cooler 70, even if the re-liquidator 31 having a small cooling capacity is used, .

Hereinafter, with reference to Fig. 5, the evaporative gas treatment system 1 of the floating gas power plant according to another embodiment of the present invention will be described in detail.

5 is a block diagram schematically illustrating an evaporative gas treatment system of a floating gas power plant according to another embodiment of the present invention.

The evaporative gas treatment system 1 of the floating gas power plant according to another embodiment of the present invention is characterized in that the evaporative gas supply line 40 is branched at the compression section 40a and connected to the power generation unit 20, And a third evaporation gas supply line 43 connected to the re-liquefaction unit 30 at the downstream end of the compression unit 40a instead of the evaporation gas supply line 41. [ The evaporative gas treatment system 1 of the floating gas power plant according to another embodiment of the present invention is characterized in that the evaporative gas supply line 40 is branched at the compression section 40a and connected to the power generation unit 20, The third evaporation gas supply line 43 connected to the re-liquefaction unit 30 at the downstream end of the compression section 40a instead of the evaporation gas supply line 41 is substantially the same as the above-described embodiment . Therefore, the description will be focused on, but unless otherwise noted, the description of the remaining components is replaced by the foregoing.

The evaporation gas supply line 40 is branched from the compression section 40a and connected to the power generation unit 20. The evaporation gas supply line 40 between the compression section 40a and the power generation unit 20 includes a cooler 70, Can be disposed. That is, the evaporation gas supply line 40 can supply the natural evaporation gas to the power generation unit 20 at a pressure lower than the pressure of the natural evaporation gas discharged from the compression section 40a. The remaining natural evaporation gas supplied to the power generation unit 20 is discharged from the compression section 40a and is supplied to the third evaporation gas supply line 43 connected to the re- Can be supplied to the re-liquidator (31) of the re-liquefaction unit (30). A control valve for controlling the flow of the natural evaporation gas is provided on the third evaporation gas supply line 43, and the operation of the control valve can be controlled by the control unit 90. The evaporation gas supply line 40 is branched from the compression section 40a to be connected to the power generation unit 20 and the third evaporation gas supply line 43 is connected to the rear end of the compression section 40a and the refueling unit 30 It is possible to supply the natural evaporation gas to the liquefaction unit 30 at a pressure higher than that of the power generation unit 20. In other words, even if the re-liquefying pressure of the fuel gas required by the re-liquefier unit 30 is higher than the supply pressure of the fuel gas required by the power generating unit 20, a separate compressor is additionally provided in the re-liquefier unit 30 There is no need to reduce costs and space utilization can be increased.

Meanwhile, the evaporative gas treatment method of the floating gas power plant may be a natural evaporation method in which the natural evaporation gas discharged from the compression unit 40a is supplied to the re-liquefaction unit 30, (C-1 ") of supplying the gas to the remelting unit 30.

The natural evaporation gas is supplied to the re-liquefaction unit 30 through the third evaporation gas supply line 43 connected to the rear end of the compression unit 40a and connected to the re-liquefaction unit 30 ((C-1) ), The re-liquefier unit 30 can compress and re-liquefy the supplied natural evaporation gas by cooling it.

While the present invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, You will understand. It is therefore to be understood that the above-described embodiments are illustrative in all aspects and not restrictive.

1: Evaporative gas treatment system of floating gas power plant
10: liquefied gas storage tank 20: power generation unit
21: first power consumption unit 22: second power consumption unit
30: Re-liquefying unit 31: Re-liquefier
40: Evaporative gas supply line 40a:
41: first evaporation gas supply line 42: second evaporation gas supply line
43: third evaporation gas supply line 50: liquefied gas supply line
50a: pump 50b: heating part
60: Loading line 70: Cooler
80: sensor unit 90: control unit
100: Floating gas power plant

Claims (13)

At least one liquefied gas storage tank for storing liquefied gas therein;
At least one of a natural evaporation gas (nBOG) generated by naturally vaporizing the liquefied gas stored in the liquefied gas storage tank and a forced evaporative gas (fBOG) generated by forcibly vaporizing the liquefied gas stored in the liquefied gas storage tank A power generation unit that is supplied with fuel gas and generates electric power; And
And a liquefaction unit for supplying power to the liquefied gas storage tank by re-liquefying the natural evaporation gas by being supplied with electric power from the power generation unit,
Wherein the remaining amount of the total generated amount of the natural vaporized gas generated in the liquefied gas storage tank is supplied to the power generating unit and the remainder is stored in the liquefied gas storage tank to maintain the internal pressure of the liquefied gas storage tank within an allowable range, And the remainder exceeding the allowable range of the gas storage tank is supplied to the refreezing unit. The apparatus according to claim 1, further comprising: a sensor unit for measuring an internal pressure of the liquefied gas storage tank;
Further comprising a control section for controlling the natural evaporation gas to be stored in the liquefied gas storage tank or supplied to the remelting unit in response to a pressure value measured from the sensor section. 3. The apparatus according to claim 2, further comprising: an evaporation gas supply line for supplying the natural evaporation gas in the liquefied gas storage tank to the power generation unit;
And a compression unit installed on the evaporation gas supply line for compressing the natural evaporation gas. 4. The evaporative gas treatment system of claim 3, further comprising a first evaporative gas supply line branched from the evaporative gas supply line upstream of the compression unit and connected to the refill liquefaction unit. 4. The evaporative gas treatment system of claim 3, further comprising a second evaporative gas supply line branched from the evaporative gas supply line at a downstream end of the compression unit and connected to the refreezing unit. 4. The apparatus according to claim 3, wherein the evaporation gas supply line supplies the natural evaporation gas to the power generation unit at a pressure lower than a pressure of the natural evaporation gas branched from the compression unit and discharged from the compression unit,
And a third evaporation gas supply line for supplying the natural evaporation gas discharged from the compression unit to the resupply unit. (A) supplying natural evaporation gas generated by spontaneously vaporizing the liquefied gas to at least one liquefied gas storage tank for storing a liquefied gas therein, to produce power by supplying the natural vaporized gas to the power generation unit as fuel gas;
(B) storing the remaining natural vaporized gas supplied to the power generation unit in the liquefied gas storage tank to maintain the internal pressure in the liquefied gas storage tank within an allowable range;
(C) supplying the natural evaporation gas remaining in the liquefied gas storage tank beyond the permissible range to the re-liquefaction unit to re-liquefy it; And
(D) supplying the re-liquefied natural vaporizing gas to the liquefied gas storage tank,
Wherein the amount of the natural evaporation gas to be re-liquefied in the re-liquefaction unit is varied corresponding to the amount of the fuel gas required in the power generating unit. The method as claimed in claim 7, wherein the step (A) comprises the step of supplying at least one of the natural evaporation gas and the forced evaporation gas generated by forcibly vaporizing the liquefied gas stored in the liquefied gas storage tank to the power generation unit Wherein the vaporized gas is treated by the evaporation method. 9. The method of claim 8, wherein after the step (B)
(B-1) the sensor unit measures the internal pressure of the liquefied gas storage tank,
(B-2) of controlling the controller to control the supply of the natural vaporizing gas to the liquefied gas storage tank or to the re-liquefaction unit in accordance with the pressure value measured by the sensor unit / RTI > 10. The method of claim 9, wherein, prior to step (C)
Further comprising: (C-0) supplying power generated by the power generation unit to the remanufacturing unit. 11. The power generation system according to claim 10, wherein the compression unit installed on the evaporation gas supply line connecting the liquefied gas storage tank and the power generation unit compresses the natural evaporation gas to supply the power generation unit,
Further comprising the step of (C-1) in which said natural evaporation gas at the upstream end of said compression section is supplied to said remanufacturing unit through a first evaporation gas supply line. 11. The power generation system according to claim 10, wherein the compression unit installed on the evaporation gas supply line connecting the liquefied gas storage tank and the power generation unit compresses the natural evaporation gas to supply the power generation unit,
(C-1 ') in which the natural evaporation gas at the downstream of the compression section is supplied to the remanufacturing unit through a second evaporation gas supply line. 11. The power generation system according to claim 10, wherein the compression unit installed on the evaporation gas supply line connecting the liquefied gas storage tank and the power generation unit compresses the natural evaporation gas to supply the power generation unit,
Wherein the evaporation gas supply line supplies the natural evaporation gas to the power generation unit at a pressure lower than the pressure of the natural evaporation gas branched from the compression unit and discharged from the compression unit, (C-1 ") supplied to the redistribution unit through a third evaporation gas supply line.

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