LNG Gasification System and One - Key Control Method

Abstract

The present application provides an LNG gasification system and a one-key control method. The LNG gasification system includes an LNG main pipeline, a plurality of liquid supply branches, a plurality of gasification branches and a control system. The liquid supply branch includes a first liquid delivery pump, a reflux pipeline and a liquid outlet pipeline; the liquid inlet end of the first liquid delivery pump is connected to an LNG source for providing liquefied natural gas, the liquid outlet end of the first liquid delivery pump is connected to the LNG source through the reflux pipeline, and the liquid outlet end of the first liquid delivery pump is connected to the LNG main pipeline through the liquid outlet pipeline. The gasification branch includes a vaporizer, a liquid inlet pipeline and a second liquid delivery pump; the liquid inlet end of the cold side of the vaporizer is connected to the LNG main pipeline through the liquid inlet pipeline, and the gas outlet end of the cold side of the vaporizer is used for outputting gaseous natural gas; the second liquid delivery pump is connected to the hot side of the vaporizer, and the second liquid delivery pump is used to provide power for the flow of the heat exchange medium on the hot side of the vaporizer. This LNG gasification system has a high degree of automation and high stability.

Description

Technical Field

[0001] The present application relates to the technical field of LNG regasification, and particularly relates to an LNG gasification system and a one-key control method. Background Art

[0002] With the rapid development of the natural gas industry, liquefied natural gas (LNG), as a clean energy source, has received increasing attention, and domestic LNG receiving stations have developed vigorously. LNG receiving stations mainly provide peak shaving services for natural gas pipelines, and have multiple functions such as LNG unloading, storage, liquid external transportation, pressurized gasification, and boil-off gas (BOG) treatment. They involve many devices and have complex and variable operating conditions. However, conventional LNG receiving stations highly rely on manual operation. During the start-stop process of LNG gasification and external transportation, parameters such as system pressure and temperature fluctuate greatly, the system stability is poor, and it is easy to impact the liquefied natural gas transmission pipeline and the natural gas transmission pipeline. Summary of the Invention

[0003] In view of the above problems existing in the prior art, the present application provides an LNG gasification system and a one-key control method, and the technical solutions adopted in the present application are as follows.

[0004] In the first aspect of the present application, an LNG gasification system is provided. The LNG gasification system includes an LNG main pipeline, a plurality of liquid supply branches, a plurality of gasification branches, and a control system;

[0005] The liquid supply branch includes a first liquid delivery pump, a return pipeline, and a liquid outlet pipeline; the liquid inlet end of the first liquid delivery pump is connected to an LNG source for providing liquefied natural gas, the liquid outlet end of the first liquid delivery pump is connected to the LNG source through the return pipeline, and the liquid outlet end of the first liquid delivery pump is connected to the LNG main pipeline through the liquid outlet pipeline;

[0006] The gasification branch includes a vaporizer, a liquid inlet pipeline, and a second liquid delivery pump; the liquid inlet end of the cold side of the vaporizer is connected to the LNG main pipeline through the liquid inlet pipeline, and the gas outlet end of the cold side of the vaporizer is used to output gaseous natural gas; the second liquid delivery pump is connected to the hot side of the vaporizer, and the second liquid delivery pump is used to provide power for the flow of the heat exchange medium on the hot side of the vaporizer;

[0007] The control system is configured to:

[0008] Based on the first gas output volume information for identifying the natural gas output flow rate, and the first status information for identifying the operating status of each of the liquid supply branches and each of the gasification branches, respectively determine a first target liquid supply branch and a first target gasification branch from the liquid supply branches and the gasification branches that are in the closed state;

[0009] Turn on the second infusion pump on the first target gasification branch line and adjust the flow rate of the second infusion pump to be greater than or equal to the first target flow rate;

[0010] Conduct the return pipeline of the first target liquid supply branch line, start the first infusion pump of the first target liquid supply branch line, and control the first infusion pump to increase the power to increase the pressure at the liquid outlet end of the first infusion pump;

[0011] When the relative difference between the pressure at the liquid outlet end of the first infusion pump and the pressure of the LNG main pipeline is less than the first threshold, open the liquid outlet pipeline of the first target liquid supply branch line and the liquid inlet pipeline of the first target gasification branch line;

[0012] Gradually reduce the opening degree of the return pipeline of the first target liquid supply branch line, simultaneously gradually increase the opening degree of the liquid inlet pipeline of the first target gasification branch line, and gradually increase the power of the first infusion pump to gradually increase the flow rate of the liquid outlet pipeline until the return pipeline of the target liquid supply branch is closed, the flow rate of the liquid outlet pipeline reaches the second target flow rate, and the flow rate of the liquid inlet pipeline of the target gasification branch reaches the third target flow rate.

[0013] In some embodiments, the control system is specifically configured as:

[0014] Linearly reduce the opening degree of the return pipeline of the first target liquid supply branch line, and simultaneously linearly increase the opening degree of the liquid inlet pipeline of the first target gasification branch line until the return pipeline of the target liquid supply branch is closed, the flow rate of the liquid outlet pipeline reaches the second target flow rate, and the flow rate of the liquid inlet pipeline of the target gasification branch reaches the third target flow rate; or

[0015] Stepwise reduce the opening degree of the return pipeline of the first target liquid supply branch line, and simultaneously stepwise increase the opening degree of the liquid inlet pipeline of the first target gasification branch line until the return pipeline of the target liquid supply branch is closed, the flow rate of the liquid outlet pipeline reaches the second target flow rate, and the flow rate of the liquid inlet pipeline of the target gasification branch reaches the third target flow rate; wherein, the single adjustment amount of the return pipeline and the single adjustment amount of the liquid inlet pipeline conform to the first target range, and the first target range is 2.5% to 10%.

[0016] In some embodiments, the control system is specifically configured as:

[0017] Check the equipment health status of the LNG source and the pipeline between the LNG source and the first infusion pump, and obtain the first inspection information;

[0018] Based on the first gas supply volume information, the first status information, and the first inspection information, determine the first target liquid supply branch line and the first target gasification branch line from the liquid supply branch line and the gasification branch line that are in the closed state, respectively.

[0019] In some embodiments, the control system is specifically configured to:

[0020] Conduct a startup inspection on the first target liquid supply branch line and the first target gasification branch line to obtain second inspection information; the startup inspection at least includes an equipment health status inspection of the first liquid delivery pump, the return pipeline, and the liquid outlet pipeline on the first target liquid supply branch line, and the vaporizer, the liquid inlet pipeline, and the second liquid delivery pump on the first target gasification branch line;

[0021] When the second inspection information meets the first startup condition, turn on the second liquid delivery pump on the first target gasification branch line.

[0022] In some embodiments, the LNG gasification system further includes an emergency protection system, and the emergency protection system is connected to the control system; the emergency protection system includes a plurality of emergency protection items, and the emergency protection system is used to perform emergency protection operations on the liquid supply branch line or the gasification branch line through the control system when any one of the emergency protection items is triggered; the control system is specifically configured to:

[0023] Obtain second status information from the emergency protection system, and the second status information is used to identify whether each of the emergency protection items is in a put-into-use state or a non-put-into-use state;

[0024] When the second detection information meets the first startup condition and the second status information meets the second startup condition, turn on the second liquid delivery pump on the first target gasification branch line.

[0025] In some embodiments, the control system is specifically configured to:

[0026] Determine the temperature of the liquid inlet end on the cold side of the vaporizer of the first target gasification branch line;

[0027] When the temperature of the liquid inlet end on the cold side of the vaporizer is lower than the second threshold, open the liquid inlet pipeline of the first target gasification branch line;

[0028] When the temperature of the liquid inlet end on the cold side of the vaporizer is higher than the second threshold, perform a precooling operation on the liquid inlet end on the cold side of the vaporizer of the first target gasification branch line.

[0029] In some embodiments, the control system is further configured to:

[0030] Determine a second target liquid supply branch line and a second target gasification branch line from the liquid supply branch line and the gasification branch line that are in the open state respectively;

[0031] Gradually increase the opening degree of the return pipeline in the second target liquid supply branch line, simultaneously gradually decrease the opening degree of the liquid inlet pipeline in the second target gasification branch line, and gradually increase the opening degree of the liquid inlet pipelines in the remaining open gasification branch lines in the LNG gasification system until the liquid inlet pipeline in the second target gasification branch line is closed;

[0032] Close the liquid supply pipeline and the first liquid delivery pump in the second target liquid supply branch line;

[0033] Close the second liquid delivery pump in the second target gasification branch line.

[0034] In some embodiments, the control system is specifically configured as follows:

[0035] Linearly increase the opening degree of the return pipeline in the second target liquid supply branch line, simultaneously linearly decrease the opening degree of the liquid inlet pipeline in the second target gasification branch line, and linearly increase the opening degree of the liquid inlet pipelines in the remaining open gasification branch lines in the LNG gasification system until the liquid inlet pipeline in the second target gasification branch line is closed; or

[0036] Gradually increase the opening degree of the return pipeline in the second target liquid supply branch line in a stepped manner, simultaneously gradually decrease the opening degree of the liquid inlet pipeline in the second target gasification branch line in a stepped manner, and gradually increase the opening degree of the liquid inlet pipelines in the remaining open gasification branch lines in the LNG gasification system in a stepped manner until the liquid inlet pipeline in the second target gasification branch line is closed; wherein, the single adjustment amount of the return pipeline and the single adjustment amount of the liquid inlet pipeline conform to the first target range, and the first target range is 2.5% to 10%.

[0037] In some embodiments, the gasification branch line further includes a cold insulation pipeline, and the cold insulation pipeline is respectively connected to the liquid inlet end of the cold side of the vaporizer and the LNG source; the control system is further configured as follows:

[0038] After the liquid inlet pipeline in the second target gasification branch line is closed, gradually increase the opening degree of the cold insulation pipeline until the flow rate of the cold insulation pipeline reaches the fourth target flow rate.

[0039] The second aspect of the present application provides a one-key control method, which is applied to an LNG gasification system. The LNG gasification system includes an LNG main pipeline, a plurality of liquid supply branch lines and a plurality of gasification branch lines;

[0040] The liquid supply branch line includes a first infusion pump, a reflux pipeline and a liquid outlet pipeline; the liquid inlet end of the first infusion pump is connected to an LNG source for providing liquefied natural gas, the liquid outlet end of the first infusion pump is connected to the LNG source through the reflux pipeline, and the liquid outlet end of the first infusion pump is connected to the LNG main pipeline through the liquid outlet pipeline;

[0041] The gasification branch line includes a vaporizer, a liquid inlet pipeline and a second infusion pump; the liquid inlet end of the cold side of the vaporizer is connected to the LNG main pipeline through the liquid inlet pipeline, and the gas outlet end of the cold side of the vaporizer is used to output gaseous natural gas; the second infusion pump is connected to the hot side of the vaporizer, and the second infusion pump is used to provide power for the flow of the heat exchange medium on the hot side of the vaporizer;

[0042] The one-key control method includes:

[0043] Based on the first gas output volume information for identifying the natural gas output flow rate and the first status information for identifying the operating status of each of the liquid supply branch lines and each of the gasification branch lines, respectively determine a first target liquid supply branch line and a first target gasification branch line from the liquid supply branch lines and the gasification branch lines in the closed state;

[0044] Start the second infusion pump on the first target gasification branch line and adjust the flow rate of the second infusion pump to be greater than or equal to the first target flow rate;

[0045] Conduct the reflux pipeline of the first target liquid supply branch line, start the first infusion pump of the first target liquid supply branch line, and control the first infusion pump to increase the power to increase the pressure at the liquid outlet end of the first infusion pump;

[0046] When the relative difference between the pressure at the liquid outlet end of the first infusion pump and the pressure of the LNG main pipeline is less than the first threshold, open the liquid outlet pipeline of the first target liquid supply branch line and the liquid inlet pipeline of the first target gasification branch line;

[0047] Gradually reduce the opening degree of the reflux pipeline of the first target liquid supply branch line, synchronously gradually increase the opening degree of the liquid inlet pipeline of the first target gasification branch line, and gradually increase the power of the first infusion pump to gradually increase the flow rate of the liquid outlet pipeline until the reflux pipeline of the target liquid supply branch is closed, the flow rate of the liquid outlet pipeline reaches the second target flow rate, and the flow rate of the liquid inlet pipeline of the target gasification branch reaches the third target flow rate.

[0048] The LNG gasification system according to the embodiments of the present application can be steadily adjusted to the target working state under the control of the control system, has a relatively high degree of automation, and avoids impacts on the LNG source, the main LNG pipeline, the vaporizer, and the LNG export pipeline during the startup and shutdown processes, so that the LNG gasification system has high stability. Description of the Drawings

[0049] Figure 1 It is a schematic structural diagram of the LNG gasification system according to the embodiments of the present application;

[0050] Figure 2 It is a flowchart of the startup process of the LNG gasification system according to the embodiments of the present application;

[0051] Figure 3 It is a flowchart of the shutdown process of the LNG gasification system according to the embodiments of the present application.

[0052] Description of the Reference Numerals:

[0053] 110 - Main LNG pipeline;

[0054] 120 - Liquid supply branch line; 121 - First liquid delivery pump; 122 - Return pipeline; 123 - First regulating valve; 124 - Liquid outlet pipeline; 125 - Second regulating valve; 126 - First cut-off valve;

[0055] 130 - Gasification branch line; 131 - Vaporizer; 132 - Liquid inlet pipeline; 133 - Third regulating valve; 134 - Second cut-off valve; 135 - Second liquid delivery pump;

[0056] 140 - Control system;

[0057] 150 - Emergency protection system. Detailed Embodiments

[0058] The present application will be further described in detail below with reference to the drawings and embodiments. It can be understood that the specific embodiments described herein are only used to explain the related invention and are not intended to limit the invention. In addition, it should be noted that for the sake of description, only parts related to the related invention are shown in the drawings.

[0059] It should be noted that, without conflict, the embodiments in the present application and the features in the embodiments can be combined with each other. The present application will be described in detail below with reference to the drawings and embodiments.

[0060] The embodiments of the present application provide an LNG gasification system, Figure 1 It is a schematic structural diagram of the LNG gasification system according to the embodiments of the present application. Refer to Figure 1As shown in the figure, the LNG gasification system according to the embodiment of the present application includes an LNG main pipeline 110, a plurality of liquid supply branch lines 120, a plurality of gasification branch lines 130, and a control system 140. It can be understood that although Figure 1 only one liquid supply branch line 120 and one gasification branch line 130 are exemplified in the figure, in actual applications, it usually includes a plurality of parallel-connected liquid supply branch lines 120 and a plurality of parallel-connected gasification branch lines 130.

[0061] The liquid supply branch line 120 includes a first liquid delivery pump 121, a return pipeline 122, and a liquid outlet pipeline 124. The liquid inlet end of the first liquid delivery pump 121 is connected to an LNG source (not shown in the figure) for providing liquefied natural gas. The liquid outlet end of the first liquid delivery pump 121 is connected to the LNG source through the return pipeline 122, and the liquid outlet end of the first liquid delivery pump 121 is connected to the LNG main pipeline 110 through the liquid outlet pipeline 124. The first liquid delivery pump 121 can transport the LNG provided by the LNG source to the return pipeline 122 and / or the liquid outlet pipeline 124. The LNG can flow back to the LNG source through the return pipeline 122, and the LNG can be transported to the LNG main pipeline 110 through the liquid outlet pipeline 124. Optionally, the LNG source includes various devices or systems such as an LNG storage tank and an LNG transmission pipeline that can provide liquefied natural gas (LNG).

[0062] Optionally, a first regulating valve 123 may be provided on the return pipeline 122, and the opening degree of the return pipeline 122 can be adjusted through the first regulating valve 123. A second regulating valve 125 may be provided on the liquid outlet pipeline 124, and the opening degree of the liquid outlet pipeline 124 can be adjusted through the second regulating valve 125. Optionally, a first cut-off valve 126 may also be provided on the liquid outlet pipeline 124, and the liquid outlet pipeline 124 can be emergently cut off through the first cut-off valve 126. For example, in case of an emergency, the liquid outlet pipeline 124 can be emergently cut off through the first cut-off valve 126.

[0063] The gasification branch line 130 includes a vaporizer 131, a liquid inlet pipeline 132, and a second liquid delivery pump 135. The liquid inlet end of the cold side of the vaporizer 131 is connected to the LNG main pipeline 110 through the liquid inlet pipeline 132. The vaporizer 131 is used to gasify LNG into gaseous natural gas, and the gas outlet end of the cold side of the vaporizer 131 is used to output gaseous natural gas. Optionally, the vaporizer 131 includes, but is not limited to, an open rack vaporizer (ORV), an intermediate medium vaporizer (IFV), a submerged combustion vaporizer (SCV), etc. Optionally, a third regulating valve 133 may be provided on the liquid inlet pipeline 132. The opening of the liquid inlet pipeline 132 can be adjusted through the third regulating valve 133, and thus the flow rate of the liquid inlet pipeline 132 can be adjusted. Optionally, a second cut-off valve 134 may also be provided on the liquid inlet pipeline 132. The liquid inlet pipeline 132 can be emergently cut off through the second cut-off valve 134. Optionally, the LNG gasification system may further include an external transmission pipeline, and the gas outlet end of the cold side of the vaporizer 131 may be connected to the external transmission pipeline.

[0064] The second liquid delivery pump 135 is connected to the hot side of the vaporizer 131, and the second liquid delivery pump 135 is used to provide power for the flow of the heat exchange medium on the hot side of the vaporizer 131. Optionally, the liquid outlet end of the second liquid delivery pump 135 may be connected to the liquid inlet end of the hot side of the vaporizer 131. The flow rate of the hot side of the vaporizer 131 can be adjusted by adjusting the power of the second liquid delivery pump 135. Optionally, the heat exchange medium includes, but is not limited to, seawater and fresh water. For example, when the LNG gasification system is arranged in a coastal area, seawater can be used as the heat exchange medium. The second liquid delivery pump 135 can pump seawater from the sea through a pipeline, and the liquid outlet end of the hot side of the vaporizer 131 can transport the low-temperature seawater back to the sea through a pipeline. Also for example, when the LNG gasification system includes a cold energy recovery system, the second liquid delivery pump 135 may be connected to the cold energy recovery system, and high-temperature water can be extracted from the cold energy recovery system. The liquid outlet end of the hot side of the vaporizer 131 can transport the low-temperature water to the cold energy recovery system.

[0065] Optionally, sensors such as temperature sensors, pressure sensors, and flow sensors may also be provided on the reflux pipeline 122, the liquid outlet pipeline 124, and the liquid inlet pipeline 132. For example, a temperature sensor may be provided at the liquid inlet end of the cold side of the vaporizer 131, and the temperature of the liquid inlet end of the cold side of the vaporizer 131 can be detected through this temperature sensor.

[0066] Optionally, the gasification branch line 130 may further include a cold insulation pipeline (not shown in the figure). The cold insulation pipeline may be respectively connected to the liquid inlet end of the cold side of the vaporizer 131 and the LNG source. A fourth regulating valve may be provided on the cold insulation pipeline, and the opening degree of the cold insulation pipeline can be adjusted through the fourth regulating valve.

[0067] The control system 140 may be electrically connected to the first liquid delivery pump 121, the second liquid delivery pump 135, the first regulating valve 123, the second regulating valve 125, the third regulating valve 133, the fourth regulating valve, the first cut-off valve 126, the second cut-off valve 134 and each sensor respectively. The control system 140 can obtain detection data such as pressure, temperature, flow rate, etc. from each sensor, and the control system 140 can also control each controlled object based on the detection data.

[0068] Optionally, the control system 140 may include a single electronic device with data processing capabilities, or the control system 140 may also be a distributed control system 140 composed of multiple electronic devices. The electronic device at least includes a memory and a processor. A program is stored on the memory, and when the processor executes the program on the memory, the one-key control method of the embodiment of the present application can be realized. The processor may be a general-purpose processor, a digital signal processor, an application-specific integrated circuit (ASIC), a programmable logic device (PLD) or a combination thereof. The above PLD may be a complex programmable logic device (CPLD), a field-programmable gate array (FPGA), a generic array logic (GAL) or any combination thereof. The general-purpose processor may be a microprocessor or any conventional processor, etc. The memory may include non-permanent memory in a computer-readable medium, random access memory (RAM) and / or non-volatile memory in the form of, for example, read-only memory (ROM) or flash memory (flash RAM). The memory is an example of a computer-readable medium. The readable storage medium may be a magnetic disk, an optical disk, a DVD, a USB, a read-only memory (ROM) or a random access memory (RAM), etc. The present application does not limit the specific form of the storage medium.

[0069] Optionally, the control system 140 may further include a display unit. Through the display unit, a visual control interface can be displayed, and the process flow can be presented by device or area. The start / stop process progress can be indicated in different colors. A window for adjusting key start / stop parameters can be set in the form of a pop-up window, an editable table, etc. Different real-time states can be distinguished by different colors, and operator decision-making inquiries and execution confirmations can be carried out in the form of pop-up windows. The key start / stop parameters may be process limits of key process parameters, opening degrees of regulating valves, set values that key process parameters should reach in a certain step, number of cyclic executions, time limits, etc. The key process parameters may be current, pump bearing vibration, flow rate, pressure, temperature and their differences, ratios, etc. The real-time state feedback and prompts may be operation / judgment execution failure prompts, reasons for judgment not being established, prompts for items that need to be manually adjusted by the operator, etc.

[0070] Optionally, the LNG vaporization system may further include an emergency protection system 150, and the emergency protection system 150 is connected to the control system 140. The emergency protection system 150 includes a plurality of emergency protection items. The emergency protection system 150 is configured to perform emergency protection operations on the liquid supply branch line 120 or the vaporization branch line 130 through the control system 140 when any one of the emergency protection items is triggered. The following is an exemplary list of the emergency protection items in the form of a table, and for details, see Table 1.

[0071] Table 1

[0072]

[0073]

[0074] It should be noted that the above emergency protection items are only exemplary. In actual applications, the emergency protection system 150 is not limited to including the above emergency protection items.

[0075] Optionally, the emergency protection items may also have commissioning conditions. The control system 140 may send an instruction to the emergency protection system 150 to instruct the emergency protection system 150 to switch the one or more emergency protection items to the commissioning state when the commissioning conditions of the emergency protection items in the non-commissioned state are met. Optionally, the commissioning conditions may include time conditions, operating conditions of the LNG vaporization system, etc. For example, when a certain emergency protection item is configured to be commissioned later, when the timing time reaches the corresponding time threshold, the emergency protection item is switched to the commissioning state.

[0076] Figure 2 This is a flowchart of the start-up process of the LNG vaporization system according to the embodiment of the present application. Refer to Figure 2As shown, during the startup process of the LNG vaporization system, the control system can be configured to perform the following operations.

[0077] S201, check the equipment health status of the LNG source and the pipeline between the LNG source and the first infusion pump, and obtain the first inspection information.

[0078] Optionally, the equipment health status of the LNG source can be checked, or the equipment health status of the recondenser connected to the LNG source can be checked. Additionally, the equipment health status of the pipeline between the LNG source and the first infusion pump, as well as equipment such as the low-pressure pump connected to the LNG source, can be checked.

[0079] Optionally, the equipment health status detection can be automatically completed by the control system. For example, the control system can determine the equipment health status of the LNG source and the pipeline between the LNG source and the first infusion pump based on the detection results of sensors. Or, the control system can also determine the equipment health status of the LNG source and the pipeline between the LNG source and the first infusion pump based on the on / off status of the control link between the control system and the target equipment to be inspected. Alternatively, the equipment health status of the LNG source and the pipeline between the LNG source and the first infusion pump can be manually checked, and the first inspection information can be obtained through the interface device.

[0080] Optionally, the first inspection information can be used to identify the equipment health status of the LNG source and the pipeline between the LNG source and the first infusion pump. For example, the first inspection information can be used to identify that a certain LNG source is in a normal state, a fault state, a maintenance state, etc.

[0081] S202, based on the first gas output volume information for identifying the natural gas output flow rate, the first status information for identifying the operating status of each liquid supply branch line and each vaporization branch line, and the first inspection information, respectively determine the first target liquid supply branch line and the first target vaporization branch line from the liquid supply branch lines and the vaporization branch lines that are in the closed state.

[0082] Optionally, the first gas output volume information can be used to identify the newly added natural gas output flow rate of the LNG vaporization system, or it can also be used to identify the total natural gas output flow rate of the LNG vaporization system. Optionally, the operating status of the liquid supply branch line and the vaporization branch line can include an open state, a closed state, a maintenance state, etc.

[0083] Optionally, the control system may preferably select a liquid supply branch line where the upstream LNG source and pipeline are in a normal state and itself is in a closed state. The control system may also select one or more liquid supply branch lines as the first target liquid supply branch lines from multiple closed liquid supply branch lines, and select one or more gasification branch lines as the first target gasification branch lines from multiple closed gasification branch lines based on various parameters such as the newly added natural gas output flow rate, the rated liquid supply flow rate of each liquid supply branch line, and the rated natural gas output flow rate of each gasification branch line.

[0084] S203. Conduct a startup inspection on the first target liquid supply branch line and the first target gasification branch line, obtain second inspection information, and determine whether the second inspection information meets the first startup condition.

[0085] Among them, the startup inspection at least includes the equipment health status inspection of the first liquid delivery pump, the return pipeline, and the liquid outlet pipeline on the first target liquid supply branch line, and the vaporizer, the liquid inlet pipeline, and the second liquid delivery pump on the first target gasification branch line.

[0086] Optionally, the startup detection can be executed by the control system, and all or part of the inspection items can also be executed through recognition. For example, on-site staff can conduct manual inspections on some inspection items that the control system cannot execute, and send the second inspection information to the control system through, for example, interface devices.

[0087] Optionally, based on the control links between the control system and the first liquid delivery pump, the second liquid delivery pump, the first regulating valve, the second regulating valve, the third regulating valve, the fourth regulating valve, the first cut-off valve, the second cut-off valve, and each sensor, the equipment health status of each pump, valve, and sensor can be determined, and whether the control links between the control system and each pump, valve, and sensor are in a connected state can also be determined, etc.

[0088] Optionally, it can also be determined whether the first liquid delivery pump and the second liquid delivery pump are in a powered-on state.

[0089] Optionally, the system health status of safety protection systems such as the emergency cut-off system, the fire monitoring system, and the gas detection system can also be checked.

[0090] Optionally, the startup inspection may have an approval failure, and the corresponding second inspection information may have a validity period. After the control system obtains the second inspection information, it can save the second inspection information. When the control system needs to start a certain liquid supply branch line or gasification branch line again, it can obtain the second inspection information of this liquid supply branch line or gasification branch line from the local area. If the second inspection information is still within the validity period, the startup inspection can be exempted. If the second inspection information of this liquid supply branch line or gasification branch line has exceeded the validity period, the startup inspection can be re-executed.

[0091] Optionally, the first startup condition can be used to characterize that both the first target liquid supply branch line and the first target gasification branch line are in a normal state. For example, the first startup condition may include that devices such as pumps, valves, and sensors on the first target liquid supply branch line and the first target gasification branch line are all in a normal state, and the control links of the control system with each pump, valve, sensor, etc. are all in a connected state, and so on.

[0092] S204, obtain the second status information from the emergency protection system, and determine whether the second status information meets the second startup condition. The second status information is used to identify whether each of the emergency protection items is in a put-into-use state or a non-put-into-use state.

[0093] Optionally, the second startup condition may include that the emergency protection items that do not interfere with the startup of the LNG gasification system are in a put-into-use state, and the emergency protection items that interfere with the startup of the LNG gasification system are in a non-put-into-use state. For example, the second startup condition may include that the first to eighth emergency protection items in Table 1 are in a put-into-use state, and the ninth to thirteenth emergency protection systems are in a non-put-into-use state.

[0094] S205, when the second detection information meets the first startup condition and the second status information meets the second startup condition, turn on the second liquid infusion pump on the first target gasification branch line, and adjust the flow rate of the second liquid infusion pump to be greater than or equal to the first target flow rate.

[0095] Optionally, auxiliary devices such as frequency converters can be used to adjust the flow rate of the second liquid infusion pump to the first target flow rate.

[0096] Optionally, after the flow rate of the second liquid infusion pump reaches the first target flow rate, the twelfth and thirteenth emergency protection items in Table 1 can be switched to the put-into-use state.

[0097] Optionally, when the vaporizer is an open rack vaporizer, it is also possible to detect whether the distribution of the heat exchange medium on the heat exchange fins of the vaporizer is uniform. If it is uniform, the twelfth and thirteenth emergency protection items in Table 1 can be switched to the put-into-use state. If it is not uniform, the flow rate of the second liquid infusion pump needs to be adjusted, or other measures are taken to make the distribution of the heat exchange medium on the heat exchange fins uniform, and then the twelfth and thirteenth emergency protection items in Table 1 are switched to the put-into-use state.

[0098] It should be noted that steps S203 and S204 are optional steps. One or both of them can be selected, or after determining the first target liquid supply branch line and the first target gasification branch line, the second liquid infusion pump on the first target gasification branch line can be turned on without performing steps S203 and S204.

[0099] S206. Conduct the return pipeline of the first target liquid supply branch line, start the first liquid infusion pump of the first target liquid supply branch line, and control the first liquid infusion pump to increase its power to increase the pressure at the liquid outlet end of the first liquid infusion pump, so that the relative difference between the pressure at the liquid outlet end of the first liquid infusion pump and the pressure of the LNG main pipeline is less than the first threshold value.

[0100] In the initial stage when the first liquid infusion pump in the first target liquid supply branch line is turned on, the return pipeline of the first target liquid supply branch line will be conducted. The liquid outlet end of the first liquid infusion pump is connected to the LNG source through the return pipeline, and the LNG output by the first liquid infusion pump can flow to the LNG source via the return pipeline. By gradually increasing the power of the first liquid infusion pump, gradually increasing the pressure at the liquid outlet end of the first liquid infusion pump, and gradually reducing the relative difference between the pressure at the liquid outlet end of the first liquid infusion pump and the pressure of the LNG main pipeline until the relative difference between the pressure at the liquid outlet end of the first liquid infusion pump and the pressure of the LNG main pipeline is less than the first threshold value, the purpose of pressure equalization is achieved.

[0101] Optionally, the first threshold value can be, for example, 10%. That is, when the relative difference between the pressure at the liquid outlet end of the first liquid infusion pump and the pressure of the LNG main pipeline is less than 10%, the purpose of pressure equalization is achieved.

[0102] S207. When the relative difference between the pressure at the liquid outlet end of the first liquid infusion pump and the pressure of the LNG main pipeline is less than the first threshold value, open the liquid outlet pipeline of the first target liquid supply branch line and the liquid inlet pipeline of the first target gasification branch line.

[0103] That is, after the pressure equalization is completed between the liquid outlet end of the first liquid infusion pump and the LNG main pipeline, the liquid outlet pipeline of the first target liquid supply branch line and the liquid inlet pipeline of the first target gasification branch line can be opened to establish a channel from the first liquid infusion pump to the vaporizer.

[0104] Optionally, before opening the liquid inlet pipeline of the first target gasification branch line, the temperature at the liquid inlet end of the cold side of the vaporizer of the first target gasification branch line can also be determined. If the temperature at the liquid inlet end of the cold side of the vaporizer is lower than the second threshold value, the liquid inlet pipeline of the first target gasification branch line can be opened. If the temperature at the liquid inlet end of the cold side of the vaporizer is higher than the second threshold value, a pre-cooling operation can be performed on the liquid inlet end of the cold side of the vaporizer of the first target gasification branch line. For example, the liquid inlet end of the cold side of the vaporizer can be pre-cooled by a small flow of LNG until the temperature at the liquid inlet end of the cold side of the vaporizer is less than the second threshold value, and then the liquid inlet pipeline of the first target gasification branch line is opened. Optionally, the second threshold value can be, for example, -100°C.

[0105] S208, gradually reduce the opening degree of the return pipeline of the first target liquid supply branch line, simultaneously and gradually increase the opening degree of the liquid inlet pipeline of the first target gasification branch line, and gradually increase the power of the first liquid delivery pump to gradually increase the flow rate of the liquid outlet pipeline until the return pipeline of the target liquid supply branch is closed, the flow rate of the liquid outlet pipeline reaches the second target flow rate, and the flow rate of the liquid inlet pipeline of the target gasification branch reaches the third target flow rate.

[0106] Optionally, the opening degree of the return pipeline of the first target liquid supply branch line can be linearly reduced, and the opening degree of the liquid inlet pipeline of the first target gasification branch line can be linearly increased simultaneously until the return pipeline of the target liquid supply branch is closed, the flow rate of the liquid outlet pipeline reaches the second target flow rate, and the flow rate of the liquid inlet pipeline of the target gasification branch reaches the third target flow rate. For example, the opening degree of the return pipeline of the first target liquid supply branch line can be linearly reduced at the first rate, and the opening degree of the liquid inlet pipeline of the first target gasification branch line can be increased at the first rate simultaneously.

[0107] Optionally, the opening degree of the return pipeline of the first target liquid supply branch line can also be reduced in steps, and the opening degree of the liquid inlet pipeline of the first target gasification branch line can be increased in steps simultaneously until the return pipeline of the target liquid supply branch is closed, the flow rate of the liquid outlet pipeline reaches the second target flow rate, and the flow rate of the liquid inlet pipeline of the target gasification branch reaches the third target flow rate, thereby completing the connection of the first target gasification branch line. Among them, the single adjustment amount of the return pipeline and the single adjustment amount of the liquid inlet pipeline conform to the first target range, and the first target range is 2.5% to 10%.

[0108] During the startup process of the LNG gasification system according to the embodiment of the present application, under the control of the control system, first start the second liquid delivery pump on the first target gasification branch line, and adjust the flow rate of the second liquid delivery pump to be greater than or equal to the first target flow rate, so that the heat exchange medium on the hot side of the vaporizer starts to circulate, preparing for the access of LNG.

[0109] Connect the return pipeline of the first target liquid supply branch line, start the first liquid delivery pump of the first target liquid supply branch line, control the first liquid delivery pump to increase the power to increase the pressure at the liquid outlet end of the first liquid delivery pump until the relative difference between the pressure at the liquid outlet end of the first liquid delivery pump and the pressure of the LNG main pipeline is less than the first threshold value, realizing the pressure equalization between the liquid outlet end of the first liquid delivery pump and the LNG main pipeline, and opening the liquid outlet pipeline of the first target liquid supply branch line and the liquid inlet pipeline of the first target gasification branch line can avoid the impact on the LNG main pipeline caused by the access of the first liquid delivery pump.

[0110] By gradually reducing the opening degree of the return pipeline of the first target liquid supply branch line, synchronously increasing the opening degree of the liquid inlet pipeline of the first target gasification branch line, and gradually increasing the power of the first liquid delivery pump to gradually increase the flow rate of the liquid outlet pipeline until the return pipeline of the target liquid supply branch is closed, the flow rate of the liquid outlet pipeline reaches the second target flow rate, and the flow rate of the liquid inlet pipeline of the target gasification branch reaches the third target flow rate, thereby steadily connecting the first target gasification branch line to the LNG main pipeline and steadily providing the flow rate between the first target liquid supply branch line, the LNG main pipeline, and the first target gasification branch line, so as to steadily adjust the LNG gasification system to the target working state.

[0111] In this way, not only can the automation degree of the LNG gasification system be improved, but also the LNG gasification system can be steadily adjusted to the target working state, avoiding impacts on the LNG source, the LNG main pipeline, the vaporizer, and the LNG export pipeline during the startup process, making the LNG gasification system have high stability.

[0112] In some embodiments, the control system can also be configured to:

[0113] When the number of gasification branch lines in the LNG gasification system that are in the open state changes from the first quantity to the second quantity, based on the total natural gas output flow rate of the LNG gasification system, evenly distribute the natural gas output flow rate of each gasification branch line that is in the open state;

[0114] Based on the natural gas output flow rate of each gasification branch line, determine the liquid inlet end flow rate of the cold side of the vaporizer in the gasification branch line.

[0115] In this way, when the number of gasification branch lines connected to the LNG gasification system changes, the natural gas output flow rate of each gasification branch line can be evenly redistributed, and the total output flow rate can meet the export demand.

[0116] Figure 3 This is the flowchart of the shutdown process of the LNG gasification system according to the embodiments of the present application. Refer to Figure 3 As shown, during the shutdown process of the LNG gasification system, the control system can be configured to perform the following operations.

[0117] S301, respectively determine the second target liquid supply branch line and the second target gasification branch line from the liquid supply branch lines and the gasification branch lines that are in the open state.

[0118] Optionally, second gas delivery information can be obtained. The second gas delivery information can be used to identify the reduction amount of the natural gas output flow of the LNG vaporization system, and can also be used to identify the total natural gas output flow after reduction of the LNG vaporization system. Based on the second gas delivery information, the second target liquid supply branch line and the second target vaporization branch line are determined from the liquid supply branch lines and the vaporization branch lines that are in the open state.

[0119] Optionally, third status information of each of the liquid supply branch lines and the vaporization branch lines that are in the open state can also be obtained. The third status information can be used to identify the continuous working duration, the equipment health status, etc. of the liquid supply branch line and / or the vaporization branch line. The second target liquid supply branch line and the second target vaporization branch line can be determined from the liquid supply branch lines and the vaporization branch lines that are in the open state based on the second gas delivery information and the third status information. For example, the liquid supply branch line and / or the vaporization branch line with a longer continuous working duration or close to the maintenance period can be preferentially selected to be closed.

[0120] Optionally, the control system can also respond to an operation instruction sent by a user through an input device to determine the second target liquid supply branch line and the second target vaporization branch line. That is, in practical applications, the liquid supply branch line and the vaporization branch line that need to be closed can also be manually specified by the staff.

[0121] S302, obtain fourth status information from the emergency protection system, and determine whether the fourth status information meets a first closing condition. The fourth status information is used to identify whether each of the emergency protection items is in a put-into-use state or a non-put-into-use state.

[0122] Optionally, the first closing condition may include that the emergency protection items that do not interfere with the closing of the LNG vaporization system are in the put-into-use state, and the emergency protection items that interfere with the closing of the LNG vaporization system are in the non-put-into-use state. For example, the first closing condition may include that the emergency protection items in items 1 to 8 and items 10 to 13 in Table 1 are in the put-into-use state, and the emergency protection item in item 9 in Table 1 is in the non-put-into-use state. In this way, unnecessary interference to the closing process of the LNG vaporization system by the emergency protection items can be avoided.

[0123] Optionally, under the normal operating state of the LNG vaporization system, the emergency protection measures in items 1 to 13 in Table 1 are usually all in the put-into-use state. Therefore, if the emergency protection item in item 9 in Table 1 is in the put-into-use state, an instruction can be sent to the emergency protection system through the control system to instruct the emergency protection system to switch the emergency protection item in item 9 to the non-put-into-use state.

[0124] S303. Gradually increase the opening degree of the return pipeline in the second target liquid supply branch line, simultaneously and gradually decrease the opening degree of the liquid inlet pipeline in the second target gasification branch line, and gradually increase the opening degree of the liquid inlet pipelines in the remaining open gasification branch lines in the LNG gasification system until the liquid inlet pipeline in the second target gasification branch line is closed.

[0125] By gradually increasing the opening degree of the return pipeline in the second target liquid supply branch line, the return flow rate of the LNG output by the first liquid delivery pump can be increased. Simultaneously and gradually decreasing the opening degree of the liquid inlet pipeline in the second target gasification branch line can reduce the liquid inlet end flow rate on the cold side of the vaporizer. By gradually increasing the opening degree of the liquid inlet pipelines in the remaining open gasification branch lines in the LNG gasification system, the liquid inlet end flow rate on the cold side of the vaporizers in the remaining open gasification branch lines can be increased, and the flow rate of the second target gasification branch line can be absorbed by the remaining gasification branch lines. In this way, the second target gasification branch line can be smoothly cut off, avoiding an impact on the LNG main pipeline caused by the disconnection of the second target gasification branch line, which is beneficial to maintaining the stability of the LNG gasification system.

[0126] Optionally, the opening degree of the return pipeline in the second target liquid supply branch line can be linearly increased, the opening degree of the liquid inlet pipeline in the second target gasification branch line can be linearly decreased simultaneously, and the opening degree of the liquid inlet pipelines in the remaining open gasification branch lines in the LNG gasification system can be linearly increased until the liquid inlet pipeline in the second target gasification branch line is closed. For example, the opening degree of the return pipeline in the second target liquid supply branch line can be linearly increased at the second rate, the opening degree of the liquid inlet pipeline in the second target gasification branch line can be linearly decreased at the second rate limit simultaneously, and the opening degree of the liquid inlet pipelines in the remaining open gasification branch lines in the LNG gasification system can be increased at the third rate until the liquid inlet pipeline in the second target gasification branch line is closed.

[0127] Optionally, the opening degree of the return pipeline in the second target liquid supply branch line can also be increased in steps, the opening degree of the liquid inlet pipeline in the second target gasification branch line can be decreased in steps simultaneously, and the opening degree of the liquid inlet pipelines in the remaining open gasification branch lines in the LNG gasification system can be increased in steps until the liquid inlet pipeline in the second target gasification branch line is closed. Among them, the single adjustment amount of the return pipeline and the single adjustment amount of the liquid inlet pipeline conform to the first target range, and the first target range is 2.5% to 10%.

[0128] S304. Close the liquid supply pipeline and the first liquid delivery pump in the second target liquid supply branch line.

[0129] In this way, the flow between the second target liquid supply branch line and the LNG main pipeline is completely cut off.

[0130] S305, gradually increase the opening degree of the cold insulation pipeline until the flow rate of the cold insulation pipeline reaches the fourth target flow rate.

[0131] Optionally, the opening degree of the cold insulation pipeline can be increased step by step until the flow rate of the cold insulation pipeline reaches the fourth target flow rate. Wherein, the single adjustment amount of the cold insulation pipeline conforms to the second target range, and the second target range is 2.5% to 5%. Through the cold insulation pipeline, LNG with a relatively low flow rate can be maintained to flow through the liquid inlet end of the cold side of the vaporizer, so that the temperature of the liquid inlet end of the cold side of the vaporizer is maintained below the second threshold value, and further enables the vaporizer to be started at any time, which is beneficial to shortening the system response time.

[0132] S306, close the second liquid delivery pump in the second target vaporization branch line to stop the flow of the heat exchange medium on the hot side of the vaporizer.

[0133] Optionally, before closing the second liquid delivery pump in the second target vaporization branch line, an instruction can be sent to the emergency protection system through the control system to instruct the emergency protection system to close the 10th to 13th emergency protection items to avoid the emergency protection system interfering with the closing process of the second liquid delivery pump.

[0134] During the shutdown process of the LNG vaporization system according to the embodiments of the present application, under the control of the control system, at least part of the liquid supply branch line and the vaporization branch line can be automatically and steadily shut down, avoiding impacts on the LNG source, the LNG main pipeline, the vaporizer and the LNG export pipeline during the shutdown process, so that the LNG vaporization system has high stability.

[0135] The embodiments of the present application also provide a one-key control method, which is applied to the LNG vaporization system described in any one of the above embodiments. The LNG vaporization system includes an LNG main pipeline, a plurality of liquid supply branch lines, a plurality of vaporization branch lines and a control system. Specifically, the one-key control method is executed by the control system of the LNG vaporization system.

[0136] The liquid supply branch line includes a first liquid delivery pump, a return pipeline and a liquid outlet pipeline; the liquid inlet end of the first liquid delivery pump is connected to an LNG source for providing liquefied natural gas, the liquid outlet end of the first liquid delivery pump is connected to the LNG source through the return pipeline, and the liquid outlet end of the first liquid delivery pump is connected to the LNG main pipeline through the liquid outlet pipeline.

[0137] The vaporization branch line includes a vaporizer, a liquid inlet pipeline, and a second liquid delivery pump; the liquid inlet end of the cold side of the vaporizer is connected to the LNG main pipeline through the liquid inlet pipeline, and the gas outlet end of the cold side of the vaporizer is used to output gaseous natural gas; the second liquid delivery pump is connected to the hot side of the vaporizer, and the second liquid delivery pump is used to provide power for the flow of the heat exchange medium on the hot side of the vaporizer.

[0138] The one-key control method includes:

[0139] Based on the first gas output volume information for identifying the natural gas output flow rate, and the first status information for identifying the operating status of each of the liquid supply branches and each of the gasification branches, respectively determine a first target liquid supply branch and a first target gasification branch from the liquid supply branches and the gasification branches that are in the closed state;

[0140] Turn on the second liquid infusion pump on the first target gasification branch, and adjust the flow rate of the second liquid infusion pump to be greater than or equal to the first target flow rate;

[0141] Conduct the return pipeline of the first target liquid supply branch, start the first liquid infusion pump of the first target liquid supply branch, and control the first liquid infusion pump to increase the power to increase the pressure at the liquid outlet end of the first liquid infusion pump;

[0142] When the relative difference between the pressure at the liquid outlet end of the first liquid infusion pump and the pressure of the LNG main pipeline is less than the first threshold, open the liquid outlet pipeline of the first target liquid supply branch and the liquid inlet pipeline of the first target gasification branch;

[0143] Gradually reduce the opening degree of the return pipeline of the first target liquid supply branch, simultaneously gradually increase the opening degree of the liquid inlet pipeline of the first target gasification branch, and gradually increase the power of the first liquid infusion pump to gradually increase the flow rate of the liquid outlet pipeline until the return pipeline of the target liquid supply branch is closed, the flow rate of the liquid outlet pipeline reaches the second target flow rate, and the flow rate of the liquid inlet pipeline of the target gasification branch reaches the third target flow rate.

[0144] The above embodiments are only exemplary embodiments of the present application and are not used to limit the present application. The protection scope of the present application is defined by the claims. Those skilled in the art can make various modifications or equivalent replacements within the essence and protection scope of the present application, and such modifications or equivalent replacements should also be regarded as falling within the protection scope of the present application.

Claims

1. An LNG gasification system, characterized in that, The LNG gasification system includes an LNG main pipeline, a plurality of liquid supply branches, a plurality of gasification branches, and a control system; The liquid supply branch includes a first liquid delivery pump, a return pipeline, and a liquid outlet pipeline; the inlet end of the first liquid delivery pump is connected to an LNG source for providing liquefied natural gas, the outlet end of the first liquid delivery pump is connected to the LNG source through the return pipeline, and the outlet end of the first liquid delivery pump is connected to the LNG main pipeline through the liquid outlet pipeline; The gasification branch includes a vaporizer, a liquid inlet pipeline, and a second liquid delivery pump; the inlet end of the cold side of the vaporizer is connected to the LNG main pipeline through the liquid inlet pipeline, and the gas outlet end of the cold side of the vaporizer is used to output gaseous natural gas; the second liquid delivery pump is connected to the hot side of the vaporizer, and the second liquid delivery pump is used to provide power for the flow of the heat exchange medium on the hot side of the vaporizer; The control system is configured as follows: Based on the first gas output volume information for identifying the natural gas output flow rate and the first status information for identifying the operating status of each of the liquid supply branches and each of the gasification branches, respectively determine a first target liquid supply branch and a first target gasification branch from the liquid supply branches and the gasification branches in the closed state; Turn on the second liquid delivery pump on the first target gasification branch and adjust the flow rate of the second liquid delivery pump to be greater than or equal to the first target flow rate; Conduct the return pipeline of the first target liquid supply branch, start the first liquid delivery pump of the first target liquid supply branch, and control the first liquid delivery pump to increase the power to increase the pressure at the outlet end of the first liquid delivery pump; When the relative difference between the pressure at the outlet end of the first liquid delivery pump and the pressure of the LNG main pipeline is less than the first threshold, open the liquid outlet pipeline of the first target liquid supply branch and the liquid inlet pipeline of the first target gasification branch; Gradually reduce the opening degree of the return pipeline of the first target liquid supply branch, synchronously gradually increase the opening degree of the liquid inlet pipeline of the first target gasification branch, and gradually increase the power of the first liquid delivery pump to gradually increase the flow rate of the liquid outlet pipeline until the return pipeline of the first target liquid supply branch is closed, the flow rate of the liquid outlet pipeline reaches the second target flow rate, and the flow rate of the liquid inlet pipeline of the first target gasification branch reaches the third target flow rate.

2. The LNG gasification system according to claim 1, wherein The control system is specifically configured as follows: Linearly reduce the opening degree of the return pipeline of the first target liquid supply branch, and synchronously linearly increase the opening degree of the liquid inlet pipeline of the first target gasification branch until the return pipeline of the first target liquid supply branch is closed, the flow rate of the liquid outlet pipeline reaches the second target flow rate, and the flow rate of the liquid inlet pipeline of the first target gasification branch reaches the third target flow rate; Or Gradually reduce the opening degree of the return pipeline of the first target liquid supply branch line, and simultaneously and gradually increase the opening degree of the liquid inlet pipeline of the first target gasification branch line until the return pipeline of the first target liquid supply branch line is closed, the flow rate of the liquid outlet pipeline reaches the second target flow rate, and the flow rate of the liquid inlet pipeline of the first target gasification branch line reaches the third target flow rate; wherein, the single adjustment amount of the return pipeline and the single adjustment amount of the liquid inlet pipeline conform to the first target range, and the first target range is 2.5% to 10%.

3. The LNG gasification system according to claim 1, characterized in that, The control system is specifically configured as follows: Check the equipment health status of the LNG source and the pipeline between the LNG source and the first liquid delivery pump, and obtain the first inspection information; Based on the first gas delivery volume information, the first status information, and the first inspection information, respectively determine the first target liquid supply branch line and the first target gasification branch line from the liquid supply branch lines and the gasification branch lines that are in the closed state.

4. The LNG gasification system according to claim 1, wherein The control system is specifically configured as follows: Conduct a startup inspection on the first target liquid supply branch line and the first target gasification branch line, and obtain the second inspection information; the startup inspection at least includes the equipment health status inspection of the first liquid delivery pump, the return pipeline, and the liquid outlet pipeline on the first target liquid supply branch line, and the vaporizer, the liquid inlet pipeline, and the second liquid delivery pump on the first target gasification branch line; When the second inspection information meets the first startup condition, turn on the second liquid delivery pump on the first target gasification branch line.

5. The LNG gasification system according to claim 4, wherein, The LNG gasification system further includes an emergency protection system, and the emergency protection system is connected to the control system; the emergency protection system includes a plurality of emergency protection items, and the emergency protection system is used to perform emergency protection operations on the liquid supply branch line or the gasification branch line through the control system when any one of the emergency protection items is triggered; the control system is specifically configured as follows: Obtain the second status information from the emergency protection system, and the second status information is used to identify whether each of the emergency protection items is in the put-into-use state or the non-put-into-use state; When the second detection information meets the first startup condition and the second status information meets the second startup condition, turn on the second liquid delivery pump on the first target gasification branch line.

6. The LNG gasification system according to claim 1, characterized in that, The control system is specifically configured as follows: Determine the temperature of the liquid inlet end on the cold side of the vaporizer of the first target gasification branch line; When the temperature of the liquid inlet end on the cold side of the vaporizer is lower than the second threshold, open the liquid inlet pipeline of the first target gasification branch line; When the temperature of the liquid inlet end on the cold side of the vaporizer is higher than the second threshold, perform a precooling operation on the liquid inlet end on the cold side of the vaporizer of the first target gasification branch line.

7. The LNG gasification system according to claim 1, wherein, The control system is further configured as follows: Respectively determine the second target liquid supply branch line and the second target gasification branch line from the liquid supply branch lines and the gasification branch lines that are in the open state; Gradually increase the opening degree of the reflux pipeline in the second target liquid supply branch line, simultaneously gradually decrease the opening degree of the liquid inlet pipeline in the second target gasification branch line, and gradually increase the opening degree of the liquid inlet pipelines in the remaining open gasification branch lines in the LNG gasification system until the liquid inlet pipeline in the second target gasification branch line is closed; Close the liquid supply pipeline and the first liquid delivery pump in the second target liquid supply branch line; Close the second liquid delivery pump in the second target gasification branch line.

8. The LNG gasification system according to claim 7, wherein, The control system is specifically configured as follows: Linearly increase the opening degree of the reflux pipeline in the second target liquid supply branch line, simultaneously linearly decrease the opening degree of the liquid inlet pipeline in the second target gasification branch line, and linearly increase the opening degree of the liquid inlet pipelines in the remaining open gasification branch lines in the LNG gasification system until the liquid inlet pipeline in the second target gasification branch line is closed; Or Stepwise increase the opening degree of the reflux pipeline in the second target liquid supply branch line, simultaneously stepwise decrease the opening degree of the liquid inlet pipeline in the second target gasification branch line, and stepwise increase the opening degree of the liquid inlet pipelines in the remaining open gasification branch lines in the LNG gasification system until the liquid inlet pipeline in the second target gasification branch line is closed; wherein, the single adjustment amount of the reflux pipeline and the single adjustment amount of the liquid inlet pipeline conform to the first target range, and the first target range is 2.5% to 10%.

9. The LNG gasification system according to claim 7, wherein, The gasification branch line further includes a cold insulation pipeline, and the cold insulation pipeline is respectively connected to the liquid inlet end of the cold side of the vaporizer and the LNG source; the control system is further configured as follows: After the liquid inlet pipeline in the second target gasification branch line is closed, gradually increase the opening degree of the cold insulation pipeline until the flow rate of the cold insulation pipeline reaches the fourth target flow rate.

10. A one-key control method, characterized in that, Applied to an LNG gasification system, the LNG gasification system includes an LNG main pipeline, a plurality of liquid supply branch lines and a plurality of gasification branch lines; The liquid supply branch line includes a first liquid delivery pump, a reflux pipeline and a liquid outlet pipeline; the liquid inlet end of the first liquid delivery pump is connected to an LNG source for providing liquefied natural gas, the liquid outlet end of the first liquid delivery pump is connected to the LNG source through the reflux pipeline, and the liquid outlet end of the first liquid delivery pump is connected to the LNG main pipeline through the liquid outlet pipeline; The gasification branch line includes a vaporizer, a liquid inlet pipeline, and a second liquid delivery pump; the liquid inlet end of the cold side of the vaporizer is connected to the LNG main pipeline through the liquid inlet pipeline, and the gas outlet end of the cold side of the vaporizer is used to output gaseous natural gas; The second liquid delivery pump is connected to the hot side of the vaporizer, and the second liquid delivery pump is used to provide power for the flow of the heat exchange medium on the hot side of the vaporizer; The one-key control method includes: Based on the first gas output volume information for identifying the natural gas output flow rate and the first status information for identifying the operating status of each of the liquid supply branch lines and each of the gasification branch lines, respectively determine the first target liquid supply branch line and the first target gasification branch line from the liquid supply branch lines and the gasification branch lines in the closed state; Turn on the second liquid delivery pump on the first target gasification branch line and adjust the flow rate of the second liquid delivery pump to be greater than or equal to the first target flow rate; Open the return pipeline of the first target liquid supply branch line, start the first liquid infusion pump of the first target liquid supply branch line, and control the first liquid infusion pump to increase its power to increase the pressure at the liquid outlet end of the first liquid infusion pump; When the relative difference between the pressure at the liquid outlet end of the first liquid infusion pump and the pressure of the LNG main pipeline is less than the first threshold, open the liquid outlet pipeline of the first target liquid supply branch line and the liquid inlet pipeline of the first target gasification branch line; Gradually reduce the opening degree of the return pipeline of the first target liquid supply branch line, simultaneously gradually increase the opening degree of the liquid inlet pipeline of the first target gasification branch line, and gradually increase the power of the first liquid infusion pump to gradually increase the flow rate of the liquid outlet pipeline until the return pipeline of the first target liquid supply branch line is closed, the flow rate of the liquid outlet pipeline reaches the second target flow rate, and the flow rate of the liquid inlet pipeline of the first target gasification branch line reaches the third target flow rate.

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