KR101824421B1 - Fuel gas supply system - Google Patents

Abstract

Disclosed is a fuel gas supply system capable of reducing costs of exhaust gas processing equipment. According to the present invention, the system comprises: a storage unit to store liquefied gas and evaporation gas generated therefrom; a compression unit to compress and move the evaporation gas generated from the storage unit; a recondensing unit recondensing the evaporation gas compressed in the compression unit by using supercooled liquefied gas of the storage unit; a high pressure pump unit installed in a consumer supply line connected to a consumer from the recondensing unit to pressurize the liquefied gas of the recondensing unit at a pressure equal to or greater than a required pressure of the consumer; and a heat exchange unit including an evaporator to heat the liquefied gas pressurized in the high pressure pump unit to reevaporate the liquefied gas. The recondensing unit includes: a first condensing unit mixing the liquefied gas transferred from the storage unit and the evaporated gas compressed in the compressing unit to recondense the evaporated gas; and a second condensing unit transferring heat between the liquefied gas pressurized and transferred from the high pressure pump unit and the evaporated gas compressed in the compressing unit to recondense the evaporated gas.

Description

FUEL GAS SUPPLY SYSTEM [0002]

The present invention relates to a fuel gas supply system, and more particularly, to a fuel gas supply system that recycles liquefied gas or evaporated gas to be used as fuel.

As IMO regulations on the emission of greenhouse gases and various air pollutants are strengthened, shipbuilding and marine industries are replacing the use of heavy fuel oil and diesel oil, In many cases.

Natural gas is typically a liquefied natural gas (Liquefied Natural Gas), a colorless transparent cryogenic liquid with a volume reduced to 1/600 by cooling the natural gas to about -162 degrees Celsius for ease of storage and transportation. Management and operation.

Such liquefied natural gas is contained in a storage tank installed in an insulated manner on the hull and stored and transported. However, since it is virtually impossible to completely contain the liquefied natural gas, the external heat is continuously transferred to the inside of the storage tank, and the evaporated gas generated by naturally vaporizing the liquefied natural gas is accumulated in the storage tank . It is necessary to treat and remove the evaporated gas since the evaporated gas may increase the internal pressure of the storage tank and cause deformation and damage of the storage tank.

Conventionally, evaporation gas is flowed into a vent mast provided on the upper side of a storage tank, or a method of burning evaporation gas by using a GCU (Gas Combustion Unit) has been used. However, this is not desirable from the viewpoint of energy efficiency. Therefore, a method of re-liquefying the evaporation gas by supplying the evaporation gas with the liquefied natural gas or the fuel gas to the engine of the ship respectively, or using the re- .

Patent Document 1) Korean Laid-Open Patent Publication No. 10-2008-0103500 (published on November 27, 2008)

An object of the present invention is to provide a fuel gas supply system capable of efficiently recirculating even a small amount of evaporated gas generated with a large difference depending on an operation mode.

According to an aspect of the present invention, there is provided a gas turbine comprising: a storage unit for receiving liquefied gas and evaporative gas generated therefrom; A compression unit for compressing and transferring the evaporation gas generated in the storage unit; A re-condensing unit for re-condensing the evaporated gas compressed in the compression unit using the supercooled liquefied gas of the storage unit; A high-pressure pump unit installed in a demand-supply line leading from the re-condensing unit to a customer, for pressurizing the liquefied gas in the re-condensing unit to a pressure required by the customer; And a vaporizer for heating and liquefying the pressurized liquefied gas in the high-pressure pump unit; Wherein the re-condensing unit comprises: a first condenser for mixing the liquefied gas delivered from the storage unit and the evaporated gas compressed in the compression unit to re-condense the evaporated gas; And a second condenser for re-condensing the evaporated gas by heat-exchanging the liquefied gas compressed and transferred by the high-pressure pump unit and the evaporated gas compressed by the compression unit.

Wherein the compression unit comprises: a first compression unit for compressing the evaporated gas transferred from the storage unit and sending it to the first condenser; And a second compression unit for transferring the evaporation gas to the second condenser when the evaporation gas occurs at a temperature equal to or higher than the recondensing capacity of the first condenser.

Further comprising a minimum flow line branched from a downstream end of the high pressure pump unit and circulating to the first condenser, wherein the second condenser is installed in a condensing line branched from the minimum flow line and connected to the rear end of the high pressure pump unit, And heat exchange may be performed between the liquefied gas passing through the condensation line and the evaporation gas flowing from the compression section to the first condensation section.

And the recycled evaporated gas in the second condenser can be recovered to the first condenser.

The first condenser can mix the liquefied gas pressurized by the supply pump of the storage unit with the evaporative gas compressed by the first compressor of the compressor unit to recondense all or a portion of the evaporative gas.

The compression unit may further include a high-pressure compression unit for compressing a part of the evaporation gas generated in the storage unit to a high pressure and transferring the compressed gas to a demand-supply line at a downstream end of the evaporator.

The heat exchange unit may further include a heater for heating the fluid passing through the vaporizer at a downstream end thereof to a temperature required by a customer.

According to another aspect of the present invention, there is provided a liquefied gas supply system, comprising: a liquefied gas supply line for transferring liquefied gas accommodated in a storage unit to a first condenser; An evaporation gas first supply line for transferring the evaporation gas accommodated in the storage unit to the first condenser through the first condenser; An evaporation gas second supply line for transferring the evaporation gas accommodated in the storage unit to the first condenser through the second compressor; A demand supply line for transferring the liquefied gas stored in the first condenser to a customer via a high-pressure pump unit and a vaporizer; A condensing line that branches off from the downstream end of the high-pressure pump unit of the demand-supply line and rejoins the high-pressure pump unit to bypass the pressurized liquefied gas; And a second condenser for re-condensing the evaporation gas of the evaporation gas second supply line by heat-exchanging the evaporation gas of the evaporation gas second supply line and the liquefying gas of the condensation line .

The liquefied gas supply line includes a liquefied gas first supply line and a liquefied gas second supply line, and the first condenser blows the evaporation gas stored therein to the liquefied gas second supply line, Can be recycled.

Further comprising a minimum flow line connected from the downstream end of the high pressure pump unit to the first condenser, wherein the condensing line is branched at the minimum flow line and rejoined to the downstream end of the high pressure pump unit of the demand source supply line have.

And a second condensing unit for shutting off the flow of the fluid from the evaporation gas second supply line, the condensation line, and the customer supply line to the customer when the minimum flow rate operation is performed, Pump unit, so as to enable continuous operation of the high-pressure pump unit.

The second fluid line is connected to the second supply line and the condensing line, and the second fluid line is connected to the second fluid line, And the second condenser is operated, and can be operated differently according to the operation mode.

When the amount of the evaporation gas generated in the storage unit is excessive or more than the amount that can be recondensed in the first condensing unit and the second condensing unit during the shipment operation, the excessive evaporation gas is pressurized to the high- And a vapor gas high-pressure supply line for supplying the vaporized gas directly to the downstream end.

A heater for controlling the temperature of the fuel gas supplied to the demander may be provided, and the heat exchange line may be branched from the demander supply line.

The fuel gas supply system according to the present invention can regenerate the liquefied gas and supply it to a customer (HP Fuel Gas Consumer), so that the emission of sulfur oxides (SOx) and nitrogen oxides (NOx) can do.

In addition, it is possible to effectively recondense even the supply amount of the liquefied gas, which generates a large difference according to the operation mode and generates the evaporated gas.

In addition, the evaporative gas generated during operation can be recovered and used as fuel. For example, the evaporation gas generated in various operations, especially the evaporation gas that occurs excessively during the loading operation, is introduced into the second low pressure compression unit (Aux. LP BOG Compressor) and the second condensation unit (Aux BOG Recondenser) Can be recycled and recycled.

Further, during the shipment operation, the liquefied gas passing through the second condenser is pressurized by the high pressure pump unit (HP LNG Booster Pump) and is sufficiently undercooled, so that the evaporation gas (BOG), which is transferred from the second compression unit to the first condenser, It is possible to efficiently supply the fuel gas without generating evaporation gas.

Further, since a portion of the liquefied gas passing through the high-pressure pump unit condenses the evaporated gas in the second condensed portion, the evaporated gas is recycled without using an additional energy source. In addition, energy required for re-liquefaction can be minimized.

In addition, a second condenser (BOG Recondenser) is installed for recondensing the excess evaporative gas generated during the loading operation, and it is installed in a condensing line branched from the minimum flow line, The amount of water can be minimized.

Further, in order to recycle the excess evaporative gas generated during the shipment operation, the high pressure pump unit (HP LNG Booster Pump) supplies and uses only the amount required for liquefaction through the condensing line without using the entire amount of pressurized liquefied gas, It is possible to reduce the amount of piping and minimize the size of the second condenser (Aux BOG Recondenser).

Further, since the excess evaporation gas passes through the second condensing section only during the shipment operation, there is no problem of energy loss due to pressure drop during normal operation.

Further, by providing the compression unit as the first low-pressure compression section, the second low-pressure compression section, and the three high-pressure compression sections, the compression unit can be used in accordance with the operation state. For example, unlike normal operation during the shipping operation, when the excess evaporative gas is generated, the second compressed portion is used for the remaining evaporative gas over the capacity that can be treated by the first compres- sion portion, And the second low-pressure compression unit take charge of the same. Further, in the case where the evaporation gas is generated at a capacity that can be exceeded by the capacity of the first low-pressure compression section and the second low-pressure compression section, the high-pressure compression section can be applied and used for the remaining evaporation gas.

In addition, the evaporated gas recycled through the second condenser (BOG Recondenser) can be transferred to the first condenser (Main BOG Recondenser) instead of the storage tank to reduce energy waste. That is, if the re-condensed evaporated gas is returned to the low-pressure storage tank, it is necessary to pressurize the re-condensed evaporated gas again in the low-pressure (5 kPag) environment and transfer it to the first condenser.

1 shows a fuel gas supply system according to a first embodiment of the present invention.
2 shows a fuel gas supply system according to a second embodiment of the present invention.
3 shows a normal operation state of the fuel gas supply system according to the second embodiment of the present invention.
4 shows a minimum flow operation state of the fuel gas supply system according to the second embodiment of the present invention.
FIG. 5 shows a shipping operation state of the fuel gas supply system according to the second embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In order to clearly explain the present invention, parts not related to the description are omitted from the drawings, and the width, length, thickness, etc. of the components may be exaggerated for convenience. Like reference numerals designate like elements throughout the specification.

Hereinafter, the liquefied natural gas and the evaporative gas generated from the liquefied natural gas have been described as an example to facilitate understanding of the present invention, but the present invention is not limited thereto, and various liquefied gases such as liquefied ethane gas and liquefied hydrocarbon gas, Even if evaporative gas is applied, the same technical idea should be equally understood.

1 shows a fuel gas supply system according to a first embodiment of the present invention. In the first embodiment, a storage unit 100 for storing the liquefied gas and the evaporation gas generated therefrom, a compression unit 200 for compressing and transferring the evaporation gas generated in the storage unit 100, A re-condensing unit 300 for re-condensing the evaporated gas compressed in the storage unit 100 using the supercooled liquefied gas of the storage unit 100, a desalination unit 300 for re-condensing the evaporated gas in the desalination unit 300, A high pressure pump unit 400 installed to pressurize the liquefied gas in the re-condensing unit 300 to a pressure higher than the required pressure of the customer 10 and a vaporizer 510 for heating and liquefying the liquefied gas pressurized in the high pressure pump unit 400 Condensing unit 300 mixes the liquefied gas delivered from the storage unit 100 with the evaporated gas compressed in the compression unit 200 to recondense the evaporated gas The first condenser 310, and the high-pressure pump unit 400, The second may comprise a condensing unit 320 to control the heat exchange the compressed boil-off gas in a liquefied gas transport and the compression unit 200, which is to re-condense the boil-off gas.

In other words, the fuel gas supply system according to the first embodiment of the present invention includes a liquefied gas supply line L10 for transferring the liquefied gas stored in the storage unit 100 to the first condenser 310, a storage unit 100 A first evaporation gas supply line L21 for transferring the evaporation gas accommodated in the storage unit 100 to the first condensing unit 310 via the first compression unit 210, A second gas supply line L22 for transferring the liquefied gas stored in the first condenser 310 to the first condenser 310 via the high pressure pump unit 400 and the vaporizer 510, Pressure pump unit 400 that is branched from the downstream end of the high-pressure pump unit 400 of the demand-supply line L30 and which rejoins the high-pressure pump unit 400 to bypass the liquefied gas that is pressurized by the high- Line L41 and the evaporation gas second supply line L22 and the liquefied gas in the condensation line L41 to heat the evaporation gas second supply line L22, The second may comprise a condensing unit 320 to re-condense the boil-off gas. Hereinafter, each part of the fuel gas supply system will be described in detail.

First, the customer 10 uses a vaporized gas supply line L20 or a liquefied gas supply line L10 to supply the vaporized gas to the customer 10 through a vaporized gas supply line L20 or a liquefied gas supply line L10, And may be an engine that receives the fuel gas and generates propulsive force of the ship. For example, the engine may be a gas turbine, which is a rotary type heat engine driven by high temperature and high pressure combustion gas, a high pressure gas injection engine such as an ME-GI engine, or a medium pressure fuel gas of about 15 to 17 bar, An X-DF engine capable of generating an output and generating an output may be used. However, the present invention is not limited thereto, and may include various types of engines if the engine can generate an output by receiving gaseous fuel gas.

The GCU 20 may consume the fuel gas in such a manner that it receives the fluid pressurized by the first low pressure compression unit 210 from the first supply line L21 of the evaporation gas and burns it.

The storage unit 100 will be described. The storage unit 100 may include a plurality of storage tanks 101 arranged in parallel. At this time, each of the storage tanks 101 receives the liquefied fuel from the production site of natural gas, receives and stores the liquefied fuel, and stably stores the liquefied fuel until it arrives at the destination and unloads it. In addition, the storage tank 101 may be provided with a membrane-type cargo window that is heat-treated to minimize vaporization of liquefied fuel due to external heat penetration. The liquefied fuel stored in the storage tank 101 may be used as a fuel gas for a propulsion engine, a power generation engine and a GCU of a ship as described later.

The supply pump 110 may be provided at the inlet side end of the liquefied gas supply line L10 in the storage tank 101 and may be provided adjacent to the bottom surface inside the storage tank 101 so as to improve the operation efficiency. The supply pump 110 may deliver the liquefied gas stored in the storage tank 101 to the liquefied gas supply line L10.

The circulation line 120 returns part of the liquefied gas supplied to the liquefied gas supply line L10 through the supply pump 110 to the storage tank 101 again so that the amount of liquefied gas or the amount of the liquefied gas in the first condenser 310 The amount of liquefied gas supplied to the first condenser 310 can be adjusted according to the amount of fuel required in the first condenser 10.

Next, the compression unit 200 will be described. The compression unit 200 includes a first compression unit 210 compressing the evaporated gas delivered from the storage unit 100 and sending the compressed gas to the first condenser 310, And a second compression unit 220 for transferring the evaporation gas to the second condenser 320 when the capacity of the condenser 320 is higher than the capacity.

The first low pressure compression section 210 may be provided on the evaporation gas first supply line L21 and the second low pressure compression section 220 may be respectively provided on the evaporation gas second supply line L22. At this time, the first low-pressure compression unit 210 can be operated at all times and the second low-pressure compression unit 220 can be operated only during the loading operation according to the operation mode of the present fuel gas supply system. The second low-pressure compression unit 220 and the first low-pressure compression unit 210 operate together because a large amount of evaporative gas is generated in the storage unit 100 during the shipment operation.

The re-condensing unit 300 will be described. The re-condensing unit 300 mainly includes a first condensing part 310 and a second condensing part 320.

The first condenser 310 may serve as a reservoir for temporarily storing the liquefied gas supplied from the liquefied gas supply line L10. Further, the first condenser 310 mixes the liquefied gas pressurized by the supply pump 110 of the storage unit 100 with the evaporative gas compressed by the first low-pressure compressor 210 of the compression unit 200 , All or part of the evaporated gas can be recycled. At this time, re-condensation of the incoming evaporation gas can be realized by injection of the liquefied gas supplied through the liquefied gas second supply line L12.

The second condenser 320 is provided in the condensing line L41 to be described later and is connected to the high-pressure pump unit L30 through the heat exchange with the evaporation gas first supply line L21 and the second supply line L22, It is possible to re-condense the evaporated gas flowing to the first condensing portion 310 through the evaporation gas second supply line L22 by using the liquefied gas pressurized by the first condensing portion 400.

The high pressure pump unit 400 delivers the liquefied gas stored in the first condenser 310 to the demand source supply line L30 and simultaneously supplies the liquefied gas at a pressure level corresponding to the pressure condition of the fuel gas required by the customer 10. [ The gas can be pressurized. For example, when the consumer 10 is a gas turbine, the high-pressure pump unit 400 can pressurize the liquefied gas to about 30 to 40 barg and send it to the vaporizer 510.

The heat exchange unit 500 includes a vaporizer 510 to vaporize the liquefied gas supplied from the first low pressure compartment 210 to the consumer 10 via the demand source supply line L30. The heat exchange unit 500 may further include not only the vaporizer 510 but also a heater 520 for heating the fluid passing through the vaporizer 510 to a temperature required by the consumer 10. In other words, a heat exchange line L31 is additionally provided in the demand source supply line L30 and a heater 520 is provided on the heat exchange line L31 to supply the fuel supplied to the demander 10 via the demand source supply line L30 The temperature of the gas can be controlled. The heat exchange line L31 can constantly supply the fuel supplied to the customer 10 through the customer supply line L30 at a temperature required by the customer 10. [

The liquefied gas supply line L10 connects the storage unit 100 and the recondensing unit 300 described above. Specifically, the liquefied gas supply line L10 supplies the fuel gas discharged from the supply pump 110 provided at one end to the first condenser 310. [ The liquefied gas supply line L10 may include a liquefied gas first supply line L11 and a liquefied gas second supply line L12.

The liquefied gas first supply line L11 is branched at the liquefied gas supply line L10 and connected to the lower portion of the first condenser 310 and the liquefied gas second supply line L12 is connected to the liquefied gas supply line L10, The evaporation gas supplied into the first condensing part 310 may be recycled by spraying the liquefied gas on the first condensing part 310. The first condensing part 310 is connected to the upper part of the first condensing part 310. [

The evaporation gas supply line L20 supplies the evaporation gas stored in the storage unit 100 to the compression unit 200 and supplies the evaporation gas to the evaporation gas first supply line L21 and the evaporation gas second supply line L22 .

The first evaporation gas supply line L21 may extend toward the GCU 20 from the evaporation gas supply line L20. At this time, a first low pressure compartment 210 for pressurizing and supplying the evaporation gas to the GCU 20 may be provided in the first evaporation gas supply line L21.

The first evaporation gas supply line L21 extends toward the GCU 20 and can transfer a part of the evaporation gas to the first branch line L21a and the second branch line L21b. The first branch line L21a connects the evaporation gas first supply line L21 and the evaporation gas second supply line L22 and the second branch line L21b connects the evaporation gas first supply line L21, And the first condenser 310 to transfer the evaporation gas to the second evaporation gas supply line L22 or the first condenser 310, respectively.

The evaporation gas second supply line L22 may extend from the evaporation gas supply line L20 to the first condensing section 310 via the second low pressure compression section 220 and the second condensation section 320. [ This evaporation gas second supply line L22 is used only when an excessive degree of evaporation gas to be processed in the evaporation gas first supply line L21 is generated in the storage tank 101 and the evaporation gas first supply line L21 The relative amount of fluid passing therethrough may be small. The evaporated gas passing through the evaporation gas second supply line (L22) can be recycled to the first condenser (310) by the second condenser (320).

The demand-supply line L30 pressurizes the liquefied gas passing through the first condenser 310 via the high-pressure pump unit 400, vaporizes the pressurized liquefied gas with the vaporizer 510, and supplies it to the consumer 10.

The minimum flow line L40 connected to the first condenser 310 is provided at the downstream end of the high pressure pump unit 400 of the demand line L30 and the condensation line L41 is branched from the minimum flow line L40 And can be rejoined to the downstream end of the high-pressure pump unit 400 of the demand-supply line L30.

The minimum flow line L40 may be a line that returns the liquefied gas from the downstream end of the high pressure pump unit 400 of the demand source supply line L30 to the first condenser 310 again. There is a minimum flow rate that the high-pressure pump unit 400 can continuously transfer without causing a trouble or the like, and the minimum flow rate line L40 for flowing the minimum flow rate L40 is secured, so that the high- So that it can be driven without difficulty.

The condensation line L41 is provided with a second condenser 320 for recondensing the excess evaporative gas generated in a loading operation mode to be described later, Line).

2 shows a fuel gas supply system according to a second embodiment of the present invention. The description of the second embodiment described below is the same as the description of the fuel gas supply system according to the first embodiment except for the additional description of other reference numerals, It is omitted.

When the evaporation gas is excessively generated in the storage tank 101 in the evaporation gas supply line L20, the evaporation gas is pressurized by the high-pressure compression unit 230 so as to be supplied to the downstream end of the vaporizer 510 The high-pressure gas supply line L23 may be provided. This serves as means for supplying the evaporation gas directly to the customer 10 when the evaporation gas is excessively generated in the loading operation mode to be described later.

FIG. 3 shows the normal operation state of the fuel gas supply system according to the second embodiment of the present invention, FIG. 4 shows the minimum flow operation state of the fuel gas supply system according to the second embodiment of the present invention, 5 shows the shipment operation state of the fuel gas supply system according to the second embodiment of the present invention.

Referring to this, the fuel gas supply system according to the second embodiment of the present invention can be largely operated in three operation modes: a normal operation mode, a minimum flow operation mode, and a shipping operation mode.

In the minimum flow operation mode, the flow of the fluid from the evaporation gas second supply line L22, the condensation line L41, and the demand source supply line L30 to the customer 10 is blocked, The gas can be circulated through the high pressure pump unit 400 through the minimum flow rate line L40 to enable continuous operation of the high pressure pump unit 400. [

In the normal operation mode, the flow of the fluid to the evaporation gas second supply line L22 and the condensation line L41 is interrupted, and the operation of the second condenser 320 is stopped. In the shipment operation, L22) and the condensation line L41 and activates the second condenser 320 so that it can be operated differently according to the operation mode. Hereinafter, the operation modes of the respective modes will be described in detail.

A. Normal Operation Mode

In the storage tank 101, the liquefied gas is pressurized to a predetermined pressure by the supply pump 110 and is transferred to the first condenser 310. At this time, since the liquefied gas is pressurized, it is in the state of being supercooled at the pressure, and the liquid state can be maintained even when the temperature is increased to some extent.

The boil-off gas is generated in the storage tank 101 storing the liquefied gas. The thickness of the insulation provided in the storage tank 101 and the size of the storage tank 101, The amount of evaporation gas generated varies depending on the gas storage capacity and the like. At this time, since the maximum evaporation gas generation amount (Max NBOG) is a value fixed at the time of designing, the thickness of the insulation tank, the size of the storage tank 101 and the outside air condition are values that are conservative depending on the storage capacity of the liquefied gas . ≪ / RTI >

The evaporation gas is pressurized by the first low-pressure compression unit 210 in the first evaporation gas supply line L21 and transferred to the first condenser 310. [ The evaporated gas is recycled by the supercooled liquefied gas delivered from the storage tank 101 through the feed pump 110 in the first condenser 310.

The liquefied gas in the first condenser 310 and the recondensed evaporated gas are sufficiently pressurized by the high-pressure pump unit 400 to satisfy the required pressure of the customer 10. [ The liquefied gas pressurized at a high pressure is regenerated to vapor phase in the vaporizer 510. In this case, the heat source may be seawater, heated cooling water, or the like. If necessary, the temperature of the fuel gas regenerated in the heater (520, Fuel Gas Heater) is heated to a temperature required by the consumer 10. The heat source at this time may be steam or the like.

B. Minimum Flow Circulation Mode

It is possible to operate part of the liquefied gas stored in the first condenser 310 in the high pressure pump unit 400 and the minimum flow rate line L40 in the initial operation and the standby state without turning off the high pressure pump unit 400, To the first condenser (310). In this case, the first condenser 310 does not perform the re-condensation but may store the liquefied gas temporarily and separate the evaporated gas like a suction drum.

In this mode, the liquefied gas is not large enough to recirculate the evaporated gas and recycles through the minimum flow line (L40), so that it can not perform the function of re-condensing, and the evaporated gas is entirely transferred to the GCU It can be incinerated or vented if it is not possible.

C. Loading Operation Mode

Basically, it performs the same operation as normal operation mode. In this shipment operation mode, an excessive amount of evaporative gas is generated as compared with the normal operation mode. The amount of evaporation gas generated differs depending on the loading method and the system configuration. The following three cases apply differently.

1) Evaporation gas generation amount < Capacity of the second condenser 320

Only the evaporated gas that can control the pressure and the level of the first condenser 310 is sent to the first condenser 310 using the first low pressure 1 compressor (Main LP evaporative gas compressor) (Main LP Evaporative Gas Compressor) and the second low pressure compressor (Aux.LP Evaporative Gas Compressor) to the second condenser 320 to recondense the whole amount. At this time, the refrigerant compressed by the high-pressure pump unit 400 is sucked and branched at the minimum flow rate line L40 and supplied to the second condenser 320. [

2) Capacity of the second condenser 320 <Amount of evaporation gas generated <Second condenser 320 + First condenser 310 Capacity

The evaporation gas that can be recycled in the second condenser 320 is first transferred to the second condenser 320 and the remainder is transferred to the first condenser 310 for recondensing.

3) Second condensing part 320 + First condensing part 310 Capacity <Evaporation gas generation amount

Basically, the operation is performed as in the case of 2), but the high pressure compression section 230 is directly pressurized to a high pressure and connected to the rear end of the vaporizer 510 for the amount that can be recondensed in the two condensers 310 and 320 To be transferred to the customer (10).

The operation of the fuel gas supply system according to the present invention has been described above. As described above, according to the present invention, since the liquefied gas can be regenerated and supplied to the HP (Fuel Gas Consumer) 10, it is possible to reduce the cost of the exhaust gas treatment equipment due to a small amount of sulfur oxides (SOx), nitrogen oxides .

In addition, it is possible to effectively recondense even the supply amount of the liquefied gas, which generates a large difference according to the operation mode and generates the evaporated gas.

In addition, the evaporative gas generated during operation can be recovered and used as fuel. For example, the evaporation gas generated in various operations, particularly the evaporation gas excessively generated in the loading operation, is recycled by using the second low-pressure compression section 220 and the second condensation section 320, can do.

In other words, the evaporation gas generated in various operations, particularly, the evaporation gas excessively generated during the loading operation is recycled and recycled using the second low-pressure compression unit 220 and the second condensation unit 320 . If it is directly pressurized to a high pressure without re-condensing and supplied as fuel, the energy consumption required for compression increases, which is advantageous in terms of energy efficiency. It is thermodynamically obvious that pressurizing and then vaporizing the liquid is less energy consuming than pressurizing the gas.

Since the liquefied gas passing through the second condensing unit 400 is pressurized by the HP LNG Booster Pump 400 during the shipment operation and is sufficiently undercooled, the second low-pressure compressing unit 220 to the first condensing unit 310 (BOG), the evaporation gas is not generated, so that it is possible to efficiently supply the fuel gas.

Further, since a portion of the liquefied gas passing through the high-pressure pump unit 400 condenses the evaporated gas in the second condensed portion 320, and the evaporated gas is recycled without using an additional energy source, a separate re-liquefier is required none. In addition, energy required for re-liquefaction can be minimized.

The second condenser 320 is installed in the condensing line L41 branched from the minimum flow line L40 for recondensing the excess evaporative gas generated during the loading operation. So that the amount of piping can be minimized.

In order to liquefy the excess evaporative gas generated during the shipment operation, the high pressure pump unit 400 adjusts only the amount required for liquefaction through the condensation line L41 without using all of the pressurized liquefied gas, The amount of water can be reduced and the size of the second condenser 320 can be minimized.

In addition, since the excessive evaporation gas passes through the second condenser 320 only during the shipment operation, there is no problem of energy loss due to pressure drop during normal operation.

In addition, the compression unit 200 can be divided and used in accordance with the operation state by providing three first low-pressure compression sections 210, second low-pressure compression sections 220 and high-pressure compression sections 230. For example, unlike normal operation during the shipping operation, when the excess evaporative gas is generated, the second low-pressure compres- sion unit 220 is used for the remaining evaporative gas over the capacity that can be processed by the first low-pressure compres- sion unit 210 The first low-pressure compression section 210 and the second low-pressure compression section 220 take charge of the evaporation gas. Further, when the evaporation gas is generated in a capacity that can be taken by the first low-pressure compression section 210 and the second low-pressure compression section 220, the high-pressure compression section 230 can be applied and used for the remaining evaporation gas have.

In addition, the evaporated gas recycled through the second condenser 320 can be transferred to the first condenser 310, not to the storage tank, thereby reducing energy waste. In other words, if the re-condensed evaporated gas is returned to the low-pressure storage tank 101, it is necessary to pressurize it again in the low-pressure (5 kPag) environment to the feed pump 110 and transfer it to the first condenser. .

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.

L10: liquefied gas supply line L11: liquefied gas first supply line
L12: liquefied gas second supply line L20: evaporation gas supply line
L21: First evaporation gas supply line L21a: First branch line
L21b: second branch line L22: evaporation gas second supply line
L23: Evaporation gas high pressure supply line L30: Demand supply line
L31: Heat exchange line L40: Minimum flow line
L41: condensation line 10: customer
20: GCU 100: storage unit
110: feed pump 120: circulation line
200: compression unit 210: first low pressure compression unit
220: second low-pressure compression section 230: high-pressure compression section
300: Re-condensing unit 310: First condensing part
320: second condenser 400: high pressure pump unit
500: heat exchange unit 510: vaporizer
101: Storage tank

Claims (14)

A storage unit for receiving the liquefied gas and the evaporative gas generated therefrom;
A compression unit for compressing and transferring the evaporation gas generated in the storage unit;
A re-condensing unit for re-condensing the evaporated gas compressed in the compression unit using the supercooled liquefied gas of the storage unit;
A high pressure pump unit installed in a customer supply line leading from the re-condensing unit to a customer and for pressurizing the liquefied gas of the re-condensing unit to a pressure required by the customer; And
And a heat exchanger unit having a carburetor for heating and re-heating the pressurized liquefied gas in the high-pressure pump unit,
The re-condensing unit
A first condenser for mixing the liquefied gas delivered from the storage unit and the evaporation gas compressed by the compression unit to re-condense the evaporation gas; And
A second condenser for re-condensing the evaporated gas by exchanging heat between the liquefied gas compressed and transported by the high-pressure pump unit and the evaporated gas compressed by the compressor;
And a minimum flow line branched from the downstream end of the high pressure pump unit and circulated to the first condenser,
The second condenser is installed in a condensing line branched from the minimum flow rate line and connected to the rear end of the high pressure pump unit and performs heat exchange between liquefied gas passing through the condensing line and evaporation gas flowing from the compression unit to the first condensing unit The fuel gas supply system performing the fuel gas supply system. The method according to claim 1,
The compression unit
A first low-pressure compression unit for compressing the evaporated gas transferred from the storage unit and sending it to the first condenser; And
And a second low-pressure compression section for transferring the evaporation gas to the second condenser section when the evaporation gas occurs at a temperature equal to or higher than the recondensing capacity of the first condenser section. delete The method according to claim 1,
And the recondensed evaporated gas in the second condensed portion is recovered to the first condensed portion. The method according to claim 1,
The first condenser
The liquefied gas being pressurized by the supply pump of the storage unit and the evaporation gas compressed by the first low-pressure compression section of the compression unit are recycled to recycle all or a part of the evaporation gas. The method according to claim 1,
The compression unit
Further comprising a high-pressure compression section for compressing a part of the evaporation gas generated in the storage unit to a high pressure and transferring the compressed gas to a demand-supply line at a downstream end of the evaporator. The method according to claim 1,
The heat exchange unit
Further comprising a heater for heating the fluid passing through the vaporizer at a downstream end thereof to a temperature required by a customer. A liquefied gas supply line for transferring the liquefied gas contained in the storage unit to the first condenser;
An evaporation gas first supply line for transferring the evaporation gas accommodated in the storage unit to the first condenser through the first low-pressure compression unit;
An evaporation gas second supply line for transferring the evaporation gas accommodated in the storage unit to the first condenser through the second low-pressure compression unit;
A demand supply line for transferring the liquefied gas stored in the first condenser to a customer via a high-pressure pump unit and a vaporizer;
A condensing line that branches off from the downstream end of the high-pressure pump unit of the demand-supply line and rejoins the high-pressure pump unit to bypass the pressurized liquefied gas;
A second condenser for re-condensing the evaporation gas of the evaporation gas second supply line by exchanging heat between the evaporation gas of the evaporation gas second supply line and the liquefying gas of the condensation line; And
And a minimum flow line connected from the downstream end of the high-pressure pump unit of the demand-supply line to the first condenser,
Wherein the condensing line is branched at the minimum flow rate line and rejoined to a downstream end of the high pressure pump unit of the demand source supply line. 9. The method of claim 8,
Wherein the liquefied gas supply line includes a liquefied gas first supply line and a liquefied gas second supply line,
Wherein the first condensing portion injects evaporation gas stored in the second condensing portion into the second condensing portion to spray the liquefied gas supplied from the second liquefied gas supply line and regenerate the condensed gas. delete 9. The method of claim 8,
At minimum flow rate operation
The evaporation gas second supply line, the condensation line, and the flow of the fluid from the demand supply line to the customer,
Wherein the liquefied gas stored in the first condenser is circulated through the high-pressure pump unit through the minimum flow line to enable continuous operation of the high-pressure pump unit. A liquefied gas supply line for transferring the liquefied gas contained in the storage unit to the first condenser;
An evaporation gas first supply line for transferring the evaporation gas accommodated in the storage unit to the first condenser through the first low-pressure compression unit;
An evaporation gas second supply line for transferring the evaporation gas accommodated in the storage unit to the first condenser through the second low-pressure compression unit;
A demand supply line for transferring the liquefied gas stored in the first condenser to a customer via a high-pressure pump unit and a vaporizer;
A condensing line that branches off from the downstream end of the high-pressure pump unit of the demand-supply line and rejoins the high-pressure pump unit to bypass the pressurized liquefied gas; And
And a second condenser for re-condensing the evaporation gas of the evaporation gas second supply line by exchanging heat between the evaporation gas of the evaporation gas second supply line and the liquefying gas of the condensation line,
Wherein the second condensing unit is interrupted while the flow of the fluid to the evaporation gas second supply line and the condensing line is interrupted during normal operation,
Wherein the fuel gas supply system is operated differently according to the operation mode by opening the fluid flow to the evaporation gas second supply line and the condensation line at the time of shipment operation and activating the second condensation section. 13. The method of claim 12,
During the loading operation
When the amount of the evaporation gas generated in the storage unit is excessively larger than an amount that can be recycled in the first condensing unit and the second condensing unit,
Further comprising: an evaporation gas high pressure supply line which directly pressurizes excess evaporation gas to the high pressure compression section and directly supplies it to the downstream end of the vaporizer. 13. The method according to any one of claims 8 to 12,
Further comprising a heat exchanger line provided at a downstream side of the demand source supply line, wherein the heater is provided to regulate the temperature of the fuel gas supplied to the customer.

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