A liquefied natural gas delivery system and method

Abstract

The application discloses a liquefied natural gas conveying method, characterized in that the method comprises the following steps: acquiring the liquid inlet temperature parameter, the liquid inlet pressure parameter, the pipeline length parameter between two adjacent cold pump stations and the liquid flow parameter of each cold pump station; calculating the liquid inlet temperature difference parameter and the liquid inlet pressure difference parameter of the two adjacent cold pump stations based on the liquid inlet temperature parameter and the liquid inlet pressure parameter; calculating the absorbed heat value of the liquid between the two adjacent cold pump stations based on the temperature difference parameter and the liquid flow parameter; calculating the friction heat value generated by the liquid in the pipeline based on the liquid inlet pressure difference parameter and the liquid flow parameter, calculating the pipeline heat loss value based on the temperature difference parameter and the liquid flow parameter; calculating the heat difference value of the absorbed heat value, the friction heat value and the heat loss value; judging whether the heat difference value is greater than a preset threshold value; and sending a first early warning signal if the heat difference value is greater than the preset threshold value. The application further discloses a liquefied natural gas conveying system.

Description

Technical Field

[0001] This invention relates to the field of natural gas transportation technology, and in particular to a liquefied natural gas transportation system and transportation method. Background Technology

[0002] With the diversification of energy structures and the increasing awareness of environmental protection, liquefied natural gas (LNG), as a clean and efficient energy carrier, is finding increasingly wide applications. In long-distance LNG transportation, the saturated liquid entering the pipeline partially vaporizes upon heating, resulting in a two-phase flow. This two-phase flow reduces pipeline flow, increases resistance, and can even cause gas blockage. Therefore, for cryogenic liquid transportation pipelines, especially long-distance pipelines, it is crucial to prevent liquid vaporization, i.e., to achieve single-phase flow. The method to prevent vaporization is to use high-pressure transportation, maintaining the liquid pressure above its critical pressure and the liquid temperature below its critical temperature at all times. Therefore, for long-distance transportation pipelines, in addition to pressurization stations, cooling stations are required at regular intervals to reduce the elevated liquid temperature. Pressurization and cooling stations should be built together, forming a cold pump station.

[0003] Cold pump stations divide long pipelines into shorter segments. Current monitoring technology simply relies on sensors to ensure that the pressure of liquefied natural gas (LNG) remains above its critical pressure while its temperature remains below its critical temperature. If this is the case, then that segment of the pipeline is considered normal. However, in some situations, the pipeline may be affected by external heat sources, causing localized temperature increases. If this localized heat exchange is strong enough, it could lead to localized vaporization of the LNG within the pipeline, even though the overall pressure and temperature readings may remain within safe ranges. Summary of the Invention

[0004] To address the problems existing in the prior art, the present invention provides a liquefied natural gas transportation system and transportation method.

[0005] The technical solution adopted in this invention is:

[0006] In a first aspect, this application provides a method for transporting liquefied natural gas, comprising the following:

[0007] Obtain the inlet liquid temperature parameters, inlet liquid pressure parameters, pipe length parameters between two adjacent cold pump stations, and liquid flow rate parameters for each cold pump station;

[0008] Based on the inlet liquid temperature parameters and inlet liquid pressure parameters, calculate the inlet liquid temperature difference parameters and inlet liquid pressure difference parameters of two adjacent refrigeration pump stations;

[0009] Based on the temperature difference parameter and liquid flow rate parameter, calculate the heat absorbed by the liquid between two adjacent cold pump stations;

[0010] Based on the inlet pressure differential parameter and the liquid flow rate parameter, the frictional heat generated by the liquid friction in the pipe is calculated, and based on the temperature difference parameter and the liquid flow rate parameter, the heat loss of the pipe is calculated.

[0011] Calculate the heat difference between the absorbed heat value, the frictional heat value, and the heat loss value;

[0012] Determine whether the heat difference is greater than a preset threshold;

[0013] If the heat difference is greater than a preset threshold, a first warning signal is sent.

[0014] Preferably, determining whether the heat difference is greater than a preset threshold further includes:

[0015] If the heat difference is greater than a preset threshold, then determine whether the liquid inlet temperature difference parameter is greater than a preset temperature difference threshold and whether the liquid inlet pressure difference parameter is greater than a preset pressure difference threshold.

[0016] If the inlet liquid temperature difference parameter is greater than a preset temperature difference threshold or the inlet liquid pressure difference parameter is greater than a preset pressure difference threshold, a second warning signal is sent.

[0017] Preferably, determining whether the inlet liquid temperature difference parameter is greater than a preset temperature difference threshold and whether the inlet liquid pressure difference parameter is greater than a preset pressure difference threshold further includes:

[0018] If the inlet liquid temperature difference parameter is less than or equal to a preset temperature difference threshold and the inlet liquid pressure difference parameter is less than or equal to a preset pressure difference threshold,

[0019] Then obtain the ambient temperature parameters for each pipe;

[0020] Determine whether the ambient temperature parameter meets the preset temperature threshold range. If the ambient temperature parameter does not meet the preset temperature threshold range, send a third warning signal.

[0021] Preferably, determining whether the ambient temperature parameter meets the preset temperature threshold range further includes:

[0022] If the ambient temperature parameters meet the preset temperature threshold range, calculate the inlet liquid temperature difference and inlet pressure difference between different cold pump stations, and establish an inlet liquid temperature difference dataset and an inlet pressure difference dataset.

[0023] Determine whether there are any abnormal data in the temperature difference dataset or the pressure difference dataset;

[0024] If abnormal data is found in the temperature difference dataset or pressure difference dataset, a fourth warning signal will be sent.

[0025] Secondly, this application provides a liquefied natural gas (LNG) transportation system, which applies the above-mentioned LNG transportation method, including a transportation pipeline, a cold pump station, a data acquisition device, and a data processing server. The transportation pipeline is connected to the cold pump station, the data acquisition device is connected to the transportation pipeline, and the data processing server is connected to the data acquisition device.

[0026] The pipeline is used to transport natural gas liquid, and the cold pump station is used to cool and pressurize the pipeline.

[0027] The data acquisition device is used to collect the inlet liquid temperature parameters, inlet liquid pressure parameters, pipe length parameters between two adjacent cold pump stations, and liquid flow rate parameters for each cold pump station.

[0028] The data processing server is used to calculate the inlet temperature difference and inlet pressure difference parameters of two adjacent chiller pump stations based on the inlet liquid temperature and pressure parameters; calculate the heat absorbed by the liquid between the two adjacent chiller pump stations based on the temperature difference parameters and liquid flow rate parameters; calculate the frictional heat generated by the liquid friction in the pipeline based on the inlet pressure difference parameters and liquid flow rate parameters; calculate the heat loss value of the pipeline based on the temperature difference parameters and liquid flow rate parameters; calculate the heat difference between the absorbed heat value, the frictional heat value, and the heat loss value; determine whether the heat difference value is greater than a preset threshold; if the heat difference value is greater than the preset threshold, send a first warning signal.

[0029] The beneficial effects of the present invention are at least one of the following: by real-time monitoring and calculation of key parameters such as the inlet liquid temperature, inlet liquid pressure, and temperature and pressure differences between adjacent cold pump stations, the present invention can promptly detect potential faults or abnormalities and remind operators to take corresponding measures by sending early warning signals.

[0030] This application not only focuses on the operating status of individual chilled pump stations, but also achieves comprehensive monitoring of the entire transportation process by calculating and analyzing parameters such as temperature difference, pressure difference, and heat changes between adjacent chilled pump stations. This helps to identify and resolve potential problems in a timely manner, improving transportation efficiency and quality.

[0031] By establishing datasets for inlet liquid temperature difference and inlet liquid pressure difference, and performing statistical analysis on these data, this invention can more accurately identify abnormal data and potential fault points. This helps operators quickly locate and resolve problems, reducing the time and cost of fault diagnosis. Attached Figure Description

[0032] Figure 1 This is a flowchart of the method according to Embodiment 1 of the present invention;

[0033] Figure 2 This is a flowchart of the method in Embodiment 2 of the present invention. Detailed Implementation

[0034] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0035] Example 1:

[0036] LNG long-distance pipelines require the construction of LNG pressurization pump stations along their routes. Furthermore, when saturated liquids enter the pipeline, they partially vaporize upon heating, resulting in two-phase flow. This two-phase flow reduces pipeline flow rate, increases resistance, and can even cause gas blockage. Therefore, for cryogenic liquid pipelines, especially long-distance pipelines, it is crucial to prevent liquid vaporization, i.e., to achieve single-phase flow. The method to prevent vaporization is to use high-pressure transportation, maintaining the liquid pressure above its critical pressure and the liquid temperature below its critical temperature at all times. Therefore, in addition to pressurization stations, long-distance pipelines require cooling stations at regular intervals to reduce the elevated liquid temperature. Pressurization and cooling stations should be built together, called cold pump stations. Each cold pump station is connected by a transport pipeline.

[0037] Even if sensors detect that the LNG pressure remains above its critical pressure and its temperature remains below its critical temperature in a section of the transmission pipeline between two cold pump stations, this does not guarantee that the pipeline is free of abnormalities. This application provides a method for transporting liquefied natural gas, such as... Figure 1 As shown, it includes the following steps:

[0038] S101, obtain the inlet liquid temperature parameters, inlet liquid pressure parameters, pipe length parameters between two adjacent cold pump stations, and liquid flow rate parameters for each cold pump station.

[0039] For reference, in practical applications, sensors installed on the chilled pump station and pipelines can acquire parameters such as inlet liquid temperature, inlet liquid pressure, and liquid flow rate in real time. Pipeline length parameters can be obtained manually or from the original design drawings.

[0040] S102, based on the inlet liquid temperature parameter and the inlet liquid pressure parameter, calculate the inlet liquid temperature difference parameter and the inlet liquid pressure difference parameter of two adjacent refrigeration pump stations; based on the temperature difference parameter and the liquid flow rate parameter, calculate the heat absorption value of the liquid between the two adjacent refrigeration pump stations; based on the inlet liquid pressure difference parameter and the liquid flow rate parameter, calculate the frictional heat value generated by the liquid friction in the pipeline; based on the temperature difference parameter and the liquid flow rate parameter, calculate the heat loss value of the pipeline.

[0041] For reference, the inlet liquid temperature parameters (let's say T1 and T2) and inlet liquid pressure parameters (let's say P1 and P2) of two adjacent chiller pump stations are used. These parameters are obtained through sensors installed on the chiller pump stations and pipelines.

[0042] The inlet temperature difference parameter (ΔT) is calculated as follows: ΔT = T2 - T1

[0043] Where T2 is the inlet liquid temperature of the subsequent chilled pump station, and T1 is the inlet liquid temperature of the preceding chilled pump station. The inlet liquid temperature difference reflects the temperature change of natural gas during transportation.

[0044] The differential pressure parameter (ΔP) is calculated as follows: ΔP = P1 - P2

[0045] Where P1 is the inlet pressure of the previous chiller station, and P2 is the inlet pressure of the next chiller station. The inlet pressure differential reflects the pressure loss of the fluid in the pipeline.

[0046] This step yields the inlet liquid temperature difference, the inlet liquid pressure difference, and three heat-related parameters: heat absorbed by the liquid, frictional heat, and heat loss from the pipeline. These parameters provide crucial information for subsequent heat balance analysis and early warning assessments.

[0047] S103, calculate the heat difference between the absorbed heat value, the frictional heat value, and the heat loss value.

[0048] For reference, in step S102, the following parameters were calculated:

[0049] The heat absorbed by the liquid between the two cold pump stations (Q1) represents the thermal impact of the external environment on the natural gas in the pipeline. The frictional heat value (Q2) reflects the energy loss of the fluid flowing within the pipeline. The heat loss value (Q3) represents the thermal conductivity of the pipeline system itself.

[0050] After obtaining the above parameters, calculate the heat difference (ΔQ) using the following formula:

[0051] ΔQ = Q1 - (Q2 + Q3)

[0052] ΔQ represents the state of heat balance within the piping system.

[0053] S104, determine whether the heat difference is greater than a preset threshold.

[0054] If the heat difference is greater than a preset threshold, then execute S105. Otherwise, return to execute S101.

[0055] For reference, when the value of ΔQ is close to zero, it indicates that the piping system is in good thermal balance, meaning that the absorbed heat is roughly equal to the generated frictional heat and heat loss. However, when the value of ΔQ is large, especially exceeding a preset threshold, it indicates that there may be an anomaly in the piping system, such as leakage, blockage, or other problems affecting the thermal balance.

[0056] To accurately determine whether ΔQ exceeds a preset threshold, a reasonable threshold range is pre-set based on engineering experience, piping system design requirements, and safety standards. This threshold should be able to cover fluctuations in heat differential that may occur during normal operation of the piping system, while also being sensitive enough to detect potential anomalies.

[0057] S105, send the first warning signal.

[0058] For reference, when the calculated ΔQ exceeds a preset threshold, an early warning mechanism can be automatically triggered, promptly notifying operators via audible and visual alarms, SMS messages, or emails. Upon receiving the warning, operators can quickly take appropriate measures, such as inspecting the pipeline system and adjusting delivery parameters, to ensure the safe and stable operation of the pipeline system.

[0059] Example 2:

[0060] Given that ΔQ exceeds the preset threshold, indicating an anomaly, the first consideration should be whether the sensor is faulty. Under normal circumstances, after the natural gas in the pipeline is cooled by the cooling pump station, if the temperature sensor is functioning correctly and its reading is normal, the inlet temperature difference between any two adjacent cooling pump stations should be within a reasonable range. If the inlet temperature difference parameter is greater than the preset temperature difference threshold, this may mean that the temperature sensor reading is inaccurate. Similarly, the inlet pressure differential parameter also needs to be checked. If the inlet pressure differential is greater than the preset differential pressure threshold, this may indicate a pressure sensor malfunction.

[0061] like Figure 2 As shown in S104, determining whether the heat difference is greater than a preset threshold further includes:

[0062] If the heat difference is greater than a preset threshold, then steps S105 and S106 are executed.

[0063] S106, determine whether the inlet liquid temperature difference parameter is greater than a preset temperature difference threshold or whether the inlet liquid pressure difference parameter is greater than a preset pressure difference threshold.

[0064] If the inlet liquid temperature difference parameter is greater than the preset temperature difference threshold or the inlet liquid pressure difference parameter is greater than the preset pressure difference threshold, then execute S107.

[0065] S107, send the second warning signal.

[0066] The second warning signal differs from the first warning signal (which is directly triggered by the heat difference). The second warning signal is used to indicate the possibility of sensor failure or abnormal operation of the pump station.

[0067] For reference, assuming an LNG delivery system with a preset heat difference threshold of 10 kJ, a preset inlet liquid temperature difference threshold of 5°C, and a preset inlet pressure difference threshold of 0.5 MPa, the system monitors the following data in real time:

[0068] The inlet liquid temperatures of adjacent cold pump stations A and B are -150℃ and -140℃, respectively, with inlet liquid pressures of 5MPa and 4MPa, and a liquid flow rate of 100kg / s. Based on these data, the heat difference is calculated to be 15kJ (greater than the preset threshold of 10kJ). The judgment step is then executed: the inlet liquid temperature difference parameter is calculated as: ΔT = -140℃ - (-150℃) = 10℃, which is greater than the preset temperature difference threshold of 5℃.

[0069] Calculate the pressure differential parameter: ΔP = 4MPa - 5MPa = -1MPa (Note that the negative sign here only indicates the direction of pressure reduction and does not affect the comparison of absolute values). Its absolute value is 1MPa, which is greater than the preset pressure differential threshold of 0.5MPa.

[0070] Since both the inlet liquid temperature difference and inlet liquid pressure difference parameters exceeded the preset thresholds, a potential sensor malfunction was detected, and a second warning signal was immediately sent to the operator. Upon receiving the signal, the operator could quickly check the operational status of the relevant sensors to take timely corrective measures.

[0071] It should be noted that the conventional logic for judging sensor malfunctions is to directly read the parameters of each sensor and determine whether the sensor is faulty by checking if the sensor parameters are within a preset range. However, in this embodiment, considering the possibility that sensor parameters may be abnormal, but the sensor readings are still within the preset range, it is not possible to directly determine whether the sensor is faulty by judging the sensor parameters. In this embodiment, considering that the two adjacent cold pump stations are far apart, the simultaneous malfunction of sensors in two adjacent cold pump stations is a low-probability event. Therefore, in this embodiment, the working status of the sensors is indirectly judged by comparing the parameter changes between adjacent cold pump stations. This is applicable when directly read sensor values ​​may not accurately reflect the actual situation, such as when the sensor has drift or calibration problems. If there are significant changes in parameters between adjacent cold pump stations, it is more likely that the sensor in one of the pump stations is faulty.

[0072] Example 3:

[0073] Considering that if the sensor is determined to be working normally, it is necessary to further investigate the cause of the abnormality, the method of checking whether the inlet liquid temperature difference parameter is greater than the preset temperature difference threshold and whether the inlet liquid pressure difference parameter is greater than the preset pressure difference threshold also includes: if the inlet liquid temperature difference parameter is less than or equal to the preset temperature difference threshold and the inlet liquid pressure difference parameter is less than or equal to the preset pressure difference threshold.

[0074] It should be noted that when the inlet liquid temperature difference parameter is less than or equal to the preset temperature difference threshold and the inlet liquid pressure difference parameter is less than or equal to the preset pressure difference threshold, the sensor is judged to be in normal working condition.

[0075] The ambient temperature parameters for each pipeline are acquired. Assuming the temperature and pressure differences are normal, this embodiment further acquires the ambient temperature parameters for each pipeline segment to more comprehensively assess the pipeline's condition. These ambient temperature parameters are measured using temperature sensors arranged along the pipeline.

[0076] Determine whether the ambient temperature parameter meets the preset temperature threshold range. If the ambient temperature parameter does not meet the preset temperature threshold range, send a third warning signal.

[0077] It should be noted that after obtaining the ambient temperature parameters, they are compared with the preset ambient temperature threshold range. If the ambient temperature parameters exceed this preset range, it may mean that the pipeline insulation performance is damaged or that the environment has undergone abnormal changes, which may adversely affect the LNG transportation conditions.

[0078] In this situation, a third warning signal is sent to the operator. This warning signal differs from the first warning signal, which is directly triggered by the thermal difference, or the second warning signal, which is triggered by abnormalities in the inlet liquid temperature difference or inlet liquid pressure difference. The third warning signal is used to indicate abnormal ambient temperature, reminding the operator to pay attention and take necessary measures to protect the pipeline system in a timely manner.

[0079] Considering that if the sensor and pipeline ambient temperature parameters are both normal, the problem might lie with the chiller station, the determination of whether the ambient temperature parameters meet the preset temperature threshold range also includes:

[0080] If the ambient temperature parameters meet the preset temperature threshold range, calculate the inlet liquid temperature difference and inlet pressure difference between different cold pump stations, and establish an inlet liquid temperature difference dataset and an inlet pressure difference dataset.

[0081] Determine whether there are any abnormal data in the temperature difference dataset or the pressure difference dataset;

[0082] If abnormal data is found in the temperature difference dataset or pressure difference dataset, a fourth warning signal will be sent.

[0083] It should be noted that the calculations are based on the inlet liquid temperature difference and inlet pressure difference between different refrigeration pump stations. These refrigeration pump stations may not be adjacent, but rather distributed in different sections of the LNG delivery system.

[0084] For reference, suppose an LNG delivery system has multiple refrigeration pump stations distributed across different sections, such as refrigeration pump station A, refrigeration pump station B, and refrigeration pump station C. Sensors are considered to be operating normally, and pipeline ambient temperature parameters are within normal ranges. To further investigate potential problems, the inlet liquid temperature difference and inlet liquid pressure difference between these refrigeration pump stations will be calculated. Specifically, the inlet liquid temperature difference and inlet liquid pressure difference will be calculated between refrigeration pump stations A and B, between refrigeration pump stations B and C, and between refrigeration pump stations A and C. These datasets will be statistically analyzed. It is assumed that, based on historical data and normal fluctuation ranges, the normal range for inlet liquid temperature difference is 2℃~4℃, and the normal range for inlet liquid pressure difference is 0.5MPa~0.8MPa. If the inlet liquid temperature difference or inlet liquid pressure difference between station A and station C exceeds the normal range, then these data are considered abnormal.

[0085] In this situation, the system will immediately send a fourth warning signal to the operators, indicating that there may be an abnormality in the cooling or pressurization equipment of the cold pump station between station A and station C, which may cause the natural gas liquid passing through the cold pump station to not be cooled to the preset temperature or pressurized to the preset pressure.

[0086] It should be noted that in this embodiment, even if the temperature differences from A to B and from B to C are within the normal range, the accumulation of these two temperature differences may cause the total temperature difference from A to C to exceed the normal range. In particular, if the system has a certain tolerance or allowable range for temperature differences, the superposition of two seemingly normal temperature differences may exceed the overall acceptable range.

[0087] For example, cold pump station B might act as an intermediate node, undergoing changes (such as temperature regulation or pressure adjustment) during LNG processing. These changes, individually, might not affect the temperature difference between A and B or B and C, but collectively they significantly impact the temperature difference between A and C. Therefore, by calculating the inlet liquid temperature difference and inlet liquid pressure difference between different cold pump stations, when the inlet liquid temperature difference or inlet liquid pressure difference in a certain range exceeds the preset normal range, it indicates a potential problem within that range. For example, if the inlet liquid temperature difference between cold pump station A and cold pump station C exceeds the range of 2℃ to 4℃, or the inlet liquid pressure difference exceeds the range of 0.5MPa to 0.8MPa, the system will consider this an abnormal data point, potentially indicating a problem with the cold pump station. For instance, even if the temperature differences between cold pump station A and cold pump station B and cold pump station B and cold pump station C are within the normal range, if the cumulative value of these two temperature differences differs significantly from the direct temperature difference between cold pump station A and cold pump station C, it may indicate a processing problem at the intermediate node, cold pump station B. At this point, a fourth warning signal will be sent to the staff, who will then conduct inspections.

[0088] Example 4:

[0089] This application provides a liquefied natural gas (LNG) transportation system, including a transportation pipeline, a cold pump station, a data acquisition device, and a data processing server. The transportation pipeline is connected to the cold pump station, the data acquisition device is connected to the transportation pipeline, and the data processing server is connected to the data acquisition device.

[0090] The pipeline is used to transport natural gas liquid, and the cold pump station is used to cool and pressurize the pipeline.

[0091] The data acquisition device is used to collect the inlet liquid temperature parameters, inlet liquid pressure parameters, pipe length parameters between two adjacent cold pump stations, and liquid flow rate parameters for each cold pump station; wherein, the data acquisition device includes at least a pressure sensor, a temperature sensor, and a flow sensor.

[0092] The data processing server is used to calculate the inlet temperature difference and inlet pressure difference parameters of two adjacent chiller pump stations based on the inlet liquid temperature and pressure parameters; calculate the heat absorbed by the liquid between the two adjacent chiller pump stations based on the temperature difference parameters and liquid flow rate parameters; calculate the frictional heat generated by the liquid friction in the pipeline based on the inlet pressure difference parameters and liquid flow rate parameters; calculate the heat loss value of the pipeline based on the temperature difference parameters and liquid flow rate parameters; calculate the heat difference between the absorbed heat value, the frictional heat value, and the heat loss value; determine whether the heat difference value is greater than a preset threshold; if the heat difference value is greater than the preset threshold, send a first warning signal.

[0093] The embodiments described above are merely illustrative of specific implementations of the present invention, and while the descriptions are detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention.

Claims

1. A method for transporting liquefied natural gas, characterized in that, Includes the following: Obtain the inlet liquid temperature parameters, inlet liquid pressure parameters, pipe length parameters between two adjacent cold pump stations, and liquid flow rate parameters for each cold pump station; Based on the inlet liquid temperature parameters and inlet liquid pressure parameters, calculate the inlet liquid temperature difference parameters and inlet liquid pressure difference parameters of two adjacent refrigeration pump stations; Based on the temperature difference parameter and liquid flow rate parameter, calculate the heat absorbed by the liquid between two adjacent cold pump stations; Based on the inlet pressure differential parameter and the liquid flow rate parameter, the frictional heat generated by the liquid friction in the pipe is calculated, and based on the temperature difference parameter and the liquid flow rate parameter, the heat loss of the pipe is calculated. Calculate the heat difference between the absorbed heat value, the frictional heat value, and the heat loss value; Determine whether the heat difference is greater than a preset threshold; If the heat difference is greater than a preset threshold, a first warning signal is sent; Determining whether the heat difference is greater than a preset threshold also includes: If the heat difference is greater than a preset threshold, then determine whether the liquid inlet temperature difference parameter is greater than a preset temperature difference threshold or whether the liquid inlet pressure difference parameter is greater than a preset pressure difference threshold. If the inlet liquid temperature difference parameter is greater than the preset temperature difference threshold or the inlet liquid pressure difference parameter is greater than the preset pressure difference threshold, then a second warning signal is sent. Determining whether the inlet liquid temperature difference parameter is greater than a preset temperature difference threshold or the inlet liquid pressure difference parameter is greater than a preset pressure difference threshold further includes: If the inlet liquid temperature difference parameter is less than or equal to a preset temperature difference threshold and the inlet liquid pressure difference parameter is less than or equal to a preset pressure difference threshold, Then obtain the ambient temperature parameters for each pipe; Determine whether the ambient temperature parameter meets the preset temperature threshold range. If the ambient temperature parameter does not meet the preset temperature threshold range, send a third warning signal. Determining whether the ambient temperature parameters meet the preset temperature threshold range also includes: If the ambient temperature parameters meet the preset temperature threshold range, calculate the inlet liquid temperature difference and inlet pressure difference between different cold pump stations, and establish an inlet liquid temperature difference dataset and an inlet pressure difference dataset. Determine whether there are any abnormal data in the temperature difference dataset or the pressure difference dataset; If abnormal data is found in the temperature difference dataset or pressure difference dataset, a fourth warning signal will be sent.

2. A liquefied natural gas (LNG) transportation system, characterized in that, The method for transporting liquefied natural gas according to claim 1 includes a transport pipeline, a cold pump station, a data acquisition device and a data processing server, wherein the transport pipeline is connected to the cold pump station, the data acquisition device is connected to the transport pipeline, and the data processing server is connected to the data acquisition device. The pipeline is used to transport natural gas liquid, and the cold pump station is used to cool and pressurize the pipeline. The data acquisition device is used to collect the inlet liquid temperature parameters, inlet liquid pressure parameters, pipe length parameters between two adjacent cold pump stations, and liquid flow rate parameters for each cold pump station. The data processing server is used to calculate the inlet temperature difference and inlet pressure difference parameters of two adjacent chiller pump stations based on the inlet liquid temperature and pressure parameters; calculate the heat absorbed by the liquid between the two adjacent chiller pump stations based on the temperature difference parameters and liquid flow rate parameters; calculate the frictional heat generated by the liquid friction in the pipeline based on the inlet pressure difference parameters and liquid flow rate parameters; calculate the heat loss value of the pipeline based on the temperature difference parameters and liquid flow rate parameters; calculate the heat difference between the absorbed heat value, the frictional heat value, and the heat loss value; and determine whether the heat difference value is greater than a preset threshold. If the heat difference is greater than a preset threshold, a first warning signal is sent.

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