Gas turbine operation control method when receiving LNG

Abstract

To provide a gas turbine operation control method during LNG reception by which a boil-off gas is available as a fuel without reducing combustion stability of a gas turbine (GT) during the LNG reception.SOLUTION: A gas turbine operation control method during LNG reception includes: a step S1 of determining input with LNG basic data; a step S2 of determining the input with an LNG reception signal; a step S3-1 of calculating a BOG limit fuel flow rate X1 from a BOG generation amount and a vaporizer stable flow rate in the LNG basic data; a step S4-1 of calculating first generation power W1 to be generated by actuating a GT with X1; a step S3-2 of calculating an N component limit fuel flow rate X2 from an N component % of reception liquid and an N component % of BOG in the LNG basic data; a step S4-2 of calculating second generation power W2 to be generated by actuating the GT with X2; and a step S5-2 of comparing W1, W2 with third generation power W3 based on a power supply command and determining the largest generation power.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a method for controlling gas turbine operation when LNG (liquefied natural gas) is received into an LNG tank from an LNG carrier or the like. [Background technology]

[0002] As is conventionally known, LNG (liquefied natural gas) transported from a production site by an LNG ship is transported while being kept at an extremely low temperature of -162°C or less, and then is received into an LNG tank through piping, during which a large amount of BOG (boil-off gas) is generated. Furthermore, the LNG stored in the LNG tank generates BOG due to the influence of the external environment. The BOG in the LNG tank is discharged from the LNG tank by a BOG compressor, mixed with natural gas vaporized in an LNG vaporizer, and used as fuel for a gas turbine (GT) or the like (see Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2008-286211 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, conventionally, if the N% of LNG used as fuel for gas turbines is high when it is received in an LNG tank, the N% of the fuel after passing through an LNG vaporizer will also be high, and the N% (N2 concentration) in the BOG will be higher than the N% (N2 concentration) in the liquid. If the N% of the fuel at the gas turbine inlet is high, the combustion stability of the gas turbine will decrease, and there was concern that this could cause problems in the operation of the gas turbine (ignition, extinguishing, etc.).

[0005] In addition, the amount of LNG used as fuel for gas turbines is limited by the amount of BOG generated when LNG is received into the LNG tank and the liquid LNG flow rate required for stable operation of the LNG vaporizer.

[0006] Therefore, the present invention provides a method for controlling gas turbine operation when receiving LNG, which enables the use of BOG generated when receiving LNG as fuel without reducing the combustion stability of the gas turbine when receiving LNG. [Means for solving the problem]

[0007] The method for controlling gas turbine operation during LNG reception according to the present invention comprises the steps of: an LNG basic data input determination step for determining whether or not LNG basic data has been input during operation of the gas turbine 23 based on a power supply command; an LNG receiving signal detection determination step of determining whether an LNG receiving signal for receiving LNG into the LNG tank 4 has been input after the LNG basic data has been input by the LNG basic data input determination step; a BOG limit fuel flow rate calculation step of calculating a BOG limit fuel flow rate (X1) from the BOG generation amount (Y) and the vaporizer stable flow rate (Z) in the LNG basic data when an LNG receiving signal is detected by the LNG receiving signal detection determination step; a first power generation calculation step of calculating a first power generation electric power (W1) generated by operating the gas turbine 23 at the BOG limited fuel flow rate (X1); an N-minute limited fuel flow rate calculation step of calculating an N-minute limited fuel flow rate (X2) from the N-minute % (a%) of the received liquid in the LNG basic data and the N-minute % (b%) of the BOG in the LNG basic data when an LNG receiving signal is detected by the LNG receiving signal detection determination step; a second power generation calculation step of calculating a second power generation electric power (W2) generated by operating the gas turbine 23 at the N-component limited fuel flow rate (X2); a step of determining a generated power when receiving LNG, the step of comparing the first generated power (W1), the second generated power (W2), and the third generated power (W3) based on the power supply command, and determining the largest generated power; a gas turbine operation step during LNG reception of operating the gas turbine 23 during LNG reception so as to achieve the power generation determined in the power generation determination step; It is equipped with:

[0008] Further, the method for controlling gas turbine operation during LNG reception according to the present invention comprises the steps of: an LNG receiving signal detection determination step for determining whether or not an LNG receiving signal for receiving LNG into the LNG tank 4 has been input during operation of the gas turbine 23 based on a power supply command; an LNG basic data input determination step of determining whether or not LNG basic data has been input after it is determined that an LNG receiving signal has been input in the LNG receiving signal detection determination step; an LNG receiving signal detection determination step of determining whether an LNG receiving signal for receiving LNG into the LNG tank 4 has been input after the LNG basic data has been input by the LNG basic data input determination step; a BOG limit fuel flow rate calculation step of calculating a BOG limit fuel flow rate (X1) from the BOG generation amount (Y) and the vaporizer stable flow rate (Z) in the LNG basic data when an LNG receiving signal is detected by the LNG receiving signal detection determination step; a first power generation calculation step of calculating a first power generation electric power (W1) generated by operating the gas turbine 23 at the BOG limited fuel flow rate (X1); an N-minute limited fuel flow rate calculation step of calculating an N-minute limited fuel flow rate (X2) from the N-minute % (a%) of the received liquid in the LNG basic data and the N-minute % (b%) of the BOG in the LNG basic data when an LNG receiving signal is detected by the LNG receiving signal detection determination step; a second power generation calculation step of calculating a second power generation electric power (W2) generated by operating the gas turbine 23 at the N-component limited fuel flow rate (X2); a step of determining a generated power when receiving LNG, the step of comparing the first generated power (W1), the second generated power (W2), and the third generated power (W3) based on the power supply command, and determining the largest generated power; a gas turbine operation step during LNG reception of operating the gas turbine 23 during LNG reception so as to achieve the power generation determined in the power generation determination step; It is equipped with: Effect of the Invention

[0009] The method of controlling gas turbine operation when receiving LNG according to the present invention does not reduce the combustion stability of the gas turbine when receiving LNG, and enables the use of BOG generated when receiving LNG as fuel. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a configuration diagram of an LNG power plant used to explain a gas turbine operation control method when receiving LNG according to the present invention. [Diagram 2] FIG. 2 is a first flowchart of a method for controlling gas turbine operation during LNG reception according to the present invention. [Diagram 3] FIG. 1 is a table showing basic LNG data. [Figure 4] FIG. 4 is a diagram showing the relationship between fuel flow rate and generated power. [Diagram 5] FIG. 2 is a second flowchart of the method for controlling gas turbine operation during LNG reception according to the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

[0012] Fig. 1 is a configuration diagram of an LNG power plant 1 used to explain a method for controlling gas turbine operation when receiving LNG according to this embodiment. Fig. 2 is a first flowchart of the method for controlling gas turbine operation when receiving LNG according to this embodiment.

[0013] (Outline of LNG power plant configuration) As shown in FIG. 1, an LNG power plant 1 is configured to connect an LNG receiving pipe 3 to an LNG (liquefied natural gas) carrier 2, and receive LNG from the LNG carrier 2 into an LNG tank 4 installed on land via the LNG receiving pipe 3. The LNG receiving pipe 3 branches into an upper receiving pipe 3a and a lower receiving pipe 3b, with the upper receiving pipe 3a connected to the upper part of the LNG tank 4 and the lower receiving pipe 3b connected to the lower part of the LNG tank 4. The upper receiving pipe 3a and the lower receiving pipe 3b are selectively opened and closed by valves 5 and 6, respectively, and guide LNG discharged from a pump 8 into the LNG tank 4. Note that FIG. 1 illustrates one of a plurality of LNG tanks 4.

[0014] Since a part of the LNG flowing in from the LNG receiving pipe 3 becomes BOG, the LNG tank 4 is connected to a BOG pipe 10 at the top thereof, and a BOG compressor 11 is disposed in the middle of the BOG pipe 10, so that the BOG inside the LNG tank 4 is discharged to the outside of the LNG tank 4 by the BOG compressor 11. A pressure gauge 12 is disposed at the top of the LNG tank 4 to detect pressure fluctuations in the LNG tank 4 caused by the generation of BOG. ​​The detection result of the pressure gauge 12 is input to a CPU 13, and the operation of the BOG compressor 11 is controlled by a control signal output from the CPU 13. An outlet valve 14 and a BOG flowmeter 15 are disposed in this order in the BOG pipe 10 downstream of the BOG compressor 11. The downstream end of the BOG pipe 10 is connected to a fuel supply pipe 16. In FIG. 1, one of a plurality of BOG compressors 11 is illustrated.

[0015] Furthermore, an LNG pipe 17 is connected to the bottom of the LNG tank 4, and the LNG inside is pumped out by a pump 18 installed in the LNG pipe 17. The LNG pipe 17 is connected to an LNG vaporizer 20, and supplies LNG to the LNG vaporizer 20.

[0016] The LNG vaporizer 20 vaporizes LNG supplied from an LNG pipe to produce natural gas, and sends the natural gas to a natural gas supply pipe 21. A natural gas flowmeter 22 that measures the flow rate of the natural gas is installed in the natural gas supply pipe 21. The natural gas sent to the natural gas supply pipe 21 is mixed with BOG in the fuel supply pipe 16, and then used as fuel for the gas turbines 23 (23a, 23b). Note that FIG. 1 shows one of a plurality of LNG vaporizers 20.

[0017] The gas turbine 23 is made up of a gas turbine 23a that drives a first series generator (not shown), and a gas turbine 23b that drives a second series generator (not shown).

[0018] (Method of controlling gas turbine operation when receiving LNG) As shown in FIG. 2, in the operation control of the gas turbine when receiving LNG, first, in an LNG basic data input determination step, the CPU determines whether or not LNG basic data has been input during operation of the gas turbine based on a power supply command (step S1). When receiving LNG from an LNG carrier docked at an LNG terminal into an LNG tank, the LNG origin is reported to the operation control operator by the LNG receiving operator in advance. The operation control operator inputs LNG basic data corresponding to the LNG origin using an input device (e.g., a keyboard connected to the CPU). When the LNG basic data is input, the CPU proceeds to the next control step (step S2), and when the LNG basic data is not input, the CPU continues the operation control of the gas turbine based on the power supply command. The power supply command is a command issued from a power supply station regarding supply and demand operations, etc.

[0019] FIG. 3 is a diagram showing the LNG basic data in a table. As shown in FIG. 3, a management number is determined for each production site of LNG, and each data such as the method of receiving LNG into the LNG tank 4 (receiving LNG from the top of the LNG tank 4 or receiving LNG from the bottom of the LNG tank 4), N content % in the received liquid, N content % in the BOG, and BOG flow rate (t / h) is linked to the management number and stored in a memory device (ROM). Therefore, when an LNG receiving operator reports the production site of LNG, an operation control operator can input the management number corresponding to the production site of LNG using an input device to read the LNG basic data corresponding to the management number into the CPU 13. In FIG. 3, the LNG basic data describes the liquid type (production site), N content % in the received liquid, N content % in the BOG, and BOG flow rate so as to correspond to column numbers 1 to 5, and individual LNG basic data can be identified by combining the management number and column number. Moreover, the LNG basic data shown in Fig. 3 is data that has been determined by referring to past LNG receiving records and taking into consideration the influence of environmental conditions and the like at the time of receiving LNG. For example, the receiving method is determined (either lower receiving or upper receiving is determined) based on the density difference between the density of the receiving liquid (LNG) and the liquid density in the LNG tank 4, in addition to the liquid type. Also, since the N content % in the BOG differs depending on the receiving method (upper receiving or lower receiving), it is determined by referring to the receiving method and past receiving records, as well as taking into consideration the N content % of the LNG in the LNG tank 4, the liquid temperature difference between the receiving liquid (LNG) and the LNG in the LNG tank 4, and the like.

[0020] Next, in an LNG receiving signal detection determination step, the CPU 13 determines whether or not an LNG receiving signal for receiving LNG into the LNG tank 4 has been detected (step S2). In this embodiment, the LNG receiving signal is a detection signal from an LNG receiving piping connection detection sensor 24 that detects that the LNG receiving piping 3 has been connected to the LNG carrier ship 2, and an LNG receiving start signal input by an operation control operator. The LNG receiving start signal is input to the CPU 13 when an operation control operator on the LNG power plant 1 side turns on an LNG receiving start switch 26. The operation control operator on the LNG power plant 1 side turns on the LNG receiving start switch 26 after receiving a notification from an operator on the LNG carrier ship 2 side that the liquid sending pump 8 installed in the LNG carrier ship 2 has been started.

[0021] Next, in a BOG restricted fuel flow rate calculation step, the CPU 13 calculates a BOG restricted fuel flow rate (X1) from the BOG generation amount (BOG flow rate) (Y) in the LNG basic data and the vaporizer stable flow rate (Z) (step S3-1). The vaporizer stable flow rate is a value determined by the LNG vaporizer 20, and is stored in advance in a memory device (ROM). The BOG limit fuel flow rate (X1) is determined taking into consideration the LNG power plant consumption of the amount of BOG generated and the LNG flow rate required for stable operation of the LNG vaporizer 20, and is calculated as the sum of the amount of BOG generated (Y) and the vaporizer stable flow rate (Z) in the LNG basic data. That is, it is calculated by the following formula (Math 1). (Number 1) X1=Y+Z

[0022] Next, in a first generated electric power calculation step, the CPU 13 calculates a first generated electric power (W1) that is generated by operating the gas turbine 23 at the BOG limited fuel flow rate (X1) (step S4-1). The following formula (Equation 2) is a formula for calculating the generated power (y), and is found from experimental results showing the relationship between the fuel flow rate (x) and the generated power (y) (FIG. 4 showing the relationship between the fuel flow rate x and the generated power y). The first generated power (W1) is found as the value of y by substituting X1 for x in Equation 2. (Number 2) y=0.0072x 2 +4.8991x+70.944 In this formula 2, the unit of y is megawatt (MW). Furthermore, the unit of x is tons per hour (t / h). Furthermore, formula 2 is stored in a storage device (ROM), and the generated power (y) is calculated by the CPU 13. Furthermore, formula 2 is a formula that takes into consideration the thermal efficiency of the power generation unit (gas turbine 23 and generator) of the LNG power generation plant 1 according to this embodiment, and a power generation unit with a thermal efficiency different from that of this embodiment in an LNG power generation plant different from that of this embodiment will have a different formula from the above formula 2.

[0023] In addition, when an LNG receiving signal is detected in the LNG receiving signal detection judgment step, the CPU 13 calculates the N-minute limited fuel flow rate (X2) from the N-minute % (a%) of the received liquid in the LNG basic data and the N-minute % (b%) of BOG in the LNG basic data in the N-minute limited fuel flow rate calculation step (step S3-2). In the gas turbine 23, the combustion stability decreases as the N2 concentration in the fuel increases. Therefore, the fuel flow rate is determined so that the N2 concentration in the fuel at the inlet of the gas turbine 23 is 1% or less, so as to maintain the combustion stability of the gas turbine 23. Note that the N2 concentration in the fuel at the inlet of the gas turbine 23 differs depending on the type of the gas turbine 23, etc., and is not limited to 1%. The following formula (3) is a calculation formula for the N2 limit fuel flow rate (X2), and is a formula for determining the fuel flow rate that makes the N2 concentration in the fuel at the inlet of the gas turbine 23 1% or less. In the following formula (3), the BOG generation amount (t / h) is Y, the N content % in the receiving liquid (LNG) is a, and the N content % in the BOG is b. (Number 3) X2=bY / (1-(a+0.1)) In addition, in the formula for calculating the N-component limited fuel flow rate X2, the formula X2=(bY-aY) / (1-a) is simplified to X2=bY / (1-a) because aY is sufficiently small compared to bY, but in order to approximate the actual value, the denominator is changed from (1-a) to (1-(a+0.1)). If the N-component % in the liquid (LNG) sent from the outlet of the LNG tank 4 can be measured, the denominator of formula 3 is changed to (1-a).

[0024] Next, the CPU 13 calculates the second generated power (W2) generated by operating the gas turbine 23 at the N-minute limited fuel flow rate (X2) in a second generated power calculation step (step S4-2). The second generated power (W2) is obtained as the value of y in Equation 2 by substituting X2 for x.

[0025] Next, in a step of determining the power generation when LNG is received, the CPU 23 compares the first power generation (W1), the second power generation (W2), and the third power generation (W3) based on the power supply command, and determines the largest power generation as the power generation when LNG is received (step S5). In this way, determining the largest power generation as the power generation when LNG is received can accommodate a case where a large amount of BOG generated when LNG is received needs to be consumed as fuel for the gas turbine 23, and a case where the flow rate of liquid LNG (natural gas after passing through the LNG vaporizer 20) with a low N2 concentration needs to be increased to dilute the BOG when the N2 concentration in the BOG abnormally increases, and this makes it possible to stabilize the combustion in the gas turbine 23. In addition, if a large amount of BOG is generated in the LNG tank 4 when LNG is received, the pressure in the LNG tank 4 will rise too much if this large amount of BOG is left as it is, so the BOG in the LNG tank 4 is sucked in by the BOG compressor 11 to adjust the pressure in the LNG tank 4. The BOG sucked in by the BOG compressor 11 is burned and consumed in the gas turbine 23, but if the N2 concentration in the BOG becomes too high and the N2 concentration of the fuel at the inlet of the gas turbine 23 becomes high, the combustion of the gas turbine 23 will become unstable. Therefore, the fuel supplied to the gas turbine 23 is controlled so that the flow rate of natural gas with a low N2 concentration that has passed through the LNG vaporizer 20 is increased relative to the flow rate of BOG sucked in by the BOG compressor 11, and the N2 concentration at the inlet of the gas turbine 23 can be stably burned.

[0026] (1) First, as a first stage of the steps for determining the power generation amount when LNG is received, the CPU 13 compares the magnitude of the first generated power (W1) and the second generated power (W2) (step S5-1). If it determines that the first generated power (W1) is greater than or equal to the second generated power (W2), the CPU 13 proceeds to a second stage of the steps for determining the power generation amount when the next LNG is received. Next, as the second stage of the step of determining the generated power when LNG is received, the CPU 13 compares the magnitude of the first generated power (W1) and the third generated power (W3), and if it determines that the first generated power (W1) is greater than or equal to the third generated power (W3), it determines the first generated power (W1) to be the generated power when LNG is received (step S5-2). Next, the CPU 13 controls the operation of the gas turbine 23 so as to achieve the first generated power (W1) determined in step S5-2 (step S6).

[0027] (2) When the CPU 13 determines in step S5-1 that the second generated power (W2) is greater than the first generated power (W1), the process proceeds to a third stage of the step of determining the generated power when the next LNG is received. That is, as the third stage of the step of determining the generated power when LNG is received, the CPU 13 compares the magnitude of the second generated power (W2) and the third generated power (W3), and if it determines that the second generated power (W2) is greater than or equal to the third generated power (W3), it determines the second generated power (W2) to be the generated power when LNG is received (step S5-3). Next, the CPU 13 controls the operation of the gas turbine 23 so as to achieve the second generated power (W2) determined in step S5-3 (step S6).

[0028] (3) If the CPU 13 determines in step S5-2 that the third generated power (W3) is greater than the first generated power (W1), it determines the third generated power (W3) as the generated power when receiving LNG. Next, the CPU 13 controls the operation of the gas turbine 23 so as to achieve the third generated power (W3) verified in step S5-2 (step S6).

[0029] (4) If the CPU 13 determines in step S5-3 that the third generated power (W3) is greater than the second generated power (W2), it determines the third generated power (W3) as the generated power when receiving LNG. Next, the CPU 13 controls the operation of the gas turbine 23 so as to achieve the third generated power (W3) verified in step S5-3 (step S6).

[0030] Next, in step 7, the CPU 13 determines whether or not LNG reception has been completed (whether the LNG reception start switch 26 has been turned off by the operation control operator on the LNG power plant 1 side and an off signal (LNG reception completion signal) has been input from the LNG reception start switch 26).If it is determined that LNG reception has not been completed, the CPU 13 continues the operation control of the gas turbine 23 in step 6; if it is determined that LNG reception has been completed, the CPU 13 proceeds to the next step 8.

[0031] Next, in step 8, if the measurement result by the nitrogen concentration meter 25 installed in the fuel supply pipe 16 on the inlet side of the gas turbine 23 falls below α%, the CPU 13 transitions to operation control of the gas turbine 23 using a power supply command, and if the measurement result by the nitrogen concentration meter 25 exceeds α%, the CPU 13 continues operation control of the gas turbine 23 in step 6. Note that α is 1% in this embodiment, but an optimal value according to the combustion efficiency of the gas turbine 23 is selected.

[0032] (Effects of the embodiment) The method of controlling gas turbine operation when receiving LNG according to this embodiment as described above does not reduce the combustion stability of the gas turbine 23 when receiving LNG, and makes it possible to use the BOG generated when receiving LNG as fuel.

[0033] (Modification) FIG. 5 is a diagram showing a modification of the method for controlling gas turbine operation when LNG is received according to the above embodiment, and is a second flowchart of the method for controlling gas turbine operation when LNG is received.

[0034] The second flowchart of the gas turbine operation control method during LNG reception according to a modified example shown in FIG. 5 is a diagram in which step S1 and step S2 in the first flowchart of the gas turbine operation control method during LNG reception shown in FIG. 2 are interchanged.

[0035] That is, the CPU 13 determines whether or not an LNG receiving signal for receiving LNG into the LNG tank 4 has been detected in an LNG receiving signal detection determination step (step S1). In this modification, the LNG receiving signal is, as in the embodiment shown in Fig. 2, a detection signal from the LNG receiving piping connection detection sensor 24 that detects that the LNG receiving piping 3 has been connected to the LNG carrier 2, and a signal to start receiving LNG input by an operation control operator. When the CPU 13 determines that the LNG receiving signal has been detected, it displays an image or the like that prompts the operation control operator to input basic LNG data on a display device (e.g., a liquid crystal display panel) monitored by the operation control operator. When the CPU 13 determines that the LNG receiving signal has not been detected, it continues the operation control of the gas turbine 23 based on the power supply command.

[0036] Next, the CPU 13 determines whether or not the LNG basic data has been input (step S2). When the CPU 13 determines that the LNG basic data has not been input, the CPU 13 continues the operation control of the gas turbine 23 based on the power supply command.

[0037] 5 are the same as steps S3-1 to S4-1, steps S3-2 to S4-2, and steps S5 to S8 shown in FIG. 2, and therefore descriptions that overlap with those shown in FIG. 2 will be omitted.

[0038] The method for controlling gas turbine operation when receiving LNG according to this modified example as described above can provide the same effects as the method for controlling gas turbine operation when receiving LNG shown in FIG.

[0039] (Other variations) In the above embodiment and its modified examples, the LNG receiving signal is exemplified as a detection signal from the LNG receiving piping connection detection sensor 24 that detects that the LNG receiving piping 3 has been connected to the LNG carrier 2, and a signal to start LNG receiving input by an operation control operator, but is not limited to this and may be only a signal to start LNG receiving input by an operation control operator, or a signal to open either one of the valves 5 and 6. [Explanation of symbols]

[0040] 4...LNG tank, 23...gas turbine

Claims

1. an LNG basic data input determination step of determining whether or not LNG basic data has been input during operation of the gas turbine based on a power supply command; an LNG receiving signal detection determination step of determining whether an LNG receiving signal for receiving LNG into an LNG tank has been input after the LNG basic data is input by the LNG basic data input determination step; a BOG limit fuel flow rate calculation step of calculating a BOG limit fuel flow rate (X1) from a BOG generation amount (Y) and a vaporizer stable flow rate (Z) in the LNG basic data when an LNG receiving signal is detected by the LNG receiving signal detection determination step; a first power generation calculation step of calculating a first power generation electric power (W1) generated by operating the gas turbine at the BOG limited fuel flow rate (X1); an N-minute restricted fuel flow rate calculation step of calculating an N-minute restricted fuel flow rate (X2) from the N-minute % (a%) of the received liquid in the LNG basic data and the N-minute % (b%) of the BOG in the LNG basic data when an LNG receiving signal is detected by the LNG receiving signal detection determination step; a second power generation calculation step of calculating a second power generation electric power (W2) generated by operating the gas turbine at the N-minute limited fuel flow rate (X2); a power generation determination step for determining the largest power generation at the time of receiving LNG by comparing the first power generation (W1), the second power generation (W2), and the third power generation (W3) based on the power supply command; a gas turbine operation step during LNG reception of the gas turbine, which operates the gas turbine during LNG reception so as to achieve the power generation determined in the power generation determination step; A method for controlling gas turbine operation during LNG receiving, comprising:

2. an LNG receiving signal detection determination step of determining whether or not an LNG receiving signal for receiving LNG into an LNG tank has been input during operation of the gas turbine based on a power supply command; an LNG basic data input determination step of determining whether or not LNG basic data has been input after it is determined that an LNG receiving signal has been input by the LNG receiving signal detection determination step; an LNG receiving signal detection determination step of determining whether an LNG receiving signal for receiving LNG into an LNG tank has been input after the LNG basic data is input by the LNG basic data input determination step; a BOG limit fuel flow rate calculation step of calculating a BOG limit fuel flow rate (X1) from a BOG generation amount (Y) and a vaporizer stable flow rate (Z) in the LNG basic data when an LNG receiving signal is detected by the LNG receiving signal detection determination step; a first power generation calculation step of calculating a first power generation electric power (W1) generated by operating the gas turbine at the BOG limited fuel flow rate (X1); an N-minute restricted fuel flow rate calculation step of calculating an N-minute restricted fuel flow rate (X2) from the N-minute % (a%) of the received liquid in the LNG basic data and the N-minute % (b%) of the BOG in the LNG basic data when an LNG receiving signal is detected by the LNG receiving signal detection determination step; a second power generation calculation step of calculating a second power generation electric power (W2) generated by operating the gas turbine at the N-minute limited fuel flow rate (X2); a power generation determination step for determining the largest power generation at the time of receiving LNG by comparing the first power generation (W1), the second power generation (W2), and the third power generation (W3) based on the power supply command; a gas turbine operation step during LNG reception of the gas turbine, which operates the gas turbine during LNG reception so as to achieve the power generation determined in the power generation determination step; A method for controlling gas turbine operation during LNG receiving, comprising:

3. The BOG limit fuel flow rate (X1) is calculated by the sum (Y+Z) of the BOG generation amount (Y) and the carburetor stable flow rate (Z), The N-limited fuel flow rate (X2) is the N content in the fuel at the gas turbine inlet. ２ This is the fuel flow rate for making the concentration 1% or less. If the BOG generation rate (t / h) is Y, the N component % in the received liquid (LNG) is a, and the N component % in the BOG is b, then bY / (1-(a+0.1)) is obtained. The first generated power (W1) is 0.0072 (X1). ２ +4.8991(X1) +70.944, The second generated power (W2) is 0.0072 (X2) ２ +4.8991(X2)+70.944, 3. A method for controlling gas turbine operation during LNG reception according to claim 1 or 2.

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