Methods for Storing Liquefied Natural Gas
Liquefied natural gas (LNG) is a burgeoning clean energy source that has gained widespread adoption in China, driving the nation's LNG development. However, challenges in LNG storage have garnered attention, particularly with the escalating demand for natural gas in China. To ensure the secure and steady growth of LNG, it is imperative for relevant stakeholders to conduct a thorough analysis of current storage issues. Understanding the risk factors will enable the formulation of effective prevention and control strategies.
1. Analyzing the Fundamental Characteristics of Liquefied Natural Gas
Liquefied natural gas primarily comprises methane, along with small amounts of nitrogen, propane, and ethane. The specific composition and proportions of LNG can vary among different production facilities. While industry standards stipulate that methane content should not fall below 76%, LNG is not pure methane. To comprehend LNG thoroughly, it is essential to analyze its characteristics in production and storage, employing computer-related software for a more detailed understanding. Typically stored in insulated storage tanks or underground gas storage tanks, LNG storage incurs specific costs, necessitating stringent safety management during the storage process.
2. Analysis of Risk Factors in LNG Storage
Liquefied natural gas (LNG) is typically stored in double-layer cryogenic storage tanks. LNG, colorless and tasteless, is flammable and prone to vaporization.
(1) Temperature Influence
Temperature significantly impacts LNG. Elevated peripheral temperatures lead to increased pressure within the tank, raising the likelihood of LNG explosions and potential gas leakage. The leaked natural gas rapidly vaporizes, forming an easily combustible gas when combined with air. In the presence of an ignition source, a severe explosion accident can occur, resulting in casualties and economic losses.
(2) Storage Tank Impact
During the storage of liquefied gas, the storage tank itself can introduce risk factors. Loose or malfunctioning grounding devices in the storage tank can cause static electricity buildup, leading to discharges that affect LNG. In the event of a leak, explosions and fires may ensue. Additionally, if the tank wall exceeds its actual service life, corrosion may occur, reducing thickness and compromising anti-corrosion performance, making leaks more likely. The absence or malfunction of pressure gauges weakens the staff's ability to monitor real-time air pressure within the storage tank, hindering their ability to assess the impact of external temperature changes. This lack of information increases the overall risk.
(3) Storage Area Impact
Storage processes are susceptible to risk factors influenced by the storage area. Related factors include:
Inadequate protective walls in the storage area make it challenging to effectively mitigate fire or explosion consequences in the event of natural gas leakage, leading to preventable losses.
Insufficient basic equipment or poorly designed support structures in the storage tank can result in deformation and damage during storage. Tank toppling increases potential losses, elevating the risk.
The explosion-proof area serves as a safety defense line. Incomplete equipment, unreasonable design, or the absence of necessary explosion-proof tools diminish the area's effectiveness, heightening storage risks.
3. Safe Storage Practices for Liquefied Natural Gas
(1) Enhanced Stratified Detection in LNG Storage Tanks
Detecting and preventing the stratification of liquefied natural gas (LNG) in storage tanks is crucial to avoiding potential hazards. The stratification of natural gas is a leading cause of LNG rollovers, making it essential to conduct thorough detection and implement corresponding preventive measures. One effective method involves strategically placing temperature measuring points at specific heights within the storage tank, ensuring vertical spacing is less than two meters. Typically, a temperature difference of approximately 14°C signals the risk of rollovers. Additionally, detecting density differences between newly injected LNG and the gas already present in the tank, or assessing the calorific value disparity between them, aids in identifying potential rollover risks.
(2) Prevention and Control of LNG Stratification and Rollovers
During the LNG injection process into storage tanks, the injection method plays a significant role in preventing stratification or rollovers. LNG can be injected directly from the upper nozzle or from the bottom through a pipe inserted from the top. The choice of injection method depends on the specific gravity of natural gas. To prevent stratification or tumbling, heavy natural gas is typically injected from above, while lighter natural gas is injected from below. Utilizing the low-pressure pump of the LNG system to circulate gas within the tank, either in the upper or lower part, is an effective strategy to prevent stratification or rollovers. Installing a ring-mounted nozzle at the tank's top allows for precooling using a small amount of LNG before actual filling, ensuring high safety standards by minimizing stress and excessive evaporation during the filling process.
(3) Implementation of Corresponding Safety Measures
Personnel involved in LNG storage must possess a deep understanding of LNG characteristics and be aware of potential risk factors. Scientific and rational storage practices, considering specific storage conditions, involve setting appropriate temperature, flow rate, and pressure parameters. Adding alarm devices for high temperature and high pressure enhances inspection and supervision within the storage tank, ensuring equipment and pipelines remain in optimal condition. Regular checks of LNG tanks should be conducted to verify the proper installation of instruments, alarm devices, and grounding devices, thereby ensuring safe storage and minimizing accidents associated with tank-related factors.
Conclusion
The storage of liquefied natural gas (LNG) involves numerous safety considerations, emphasizing the need for a thorough analysis of various risk factors. Enhancing professionalism and standardizing storage procedures are essential steps in minimizing storage-related risks. Implementing tailored safety measures is crucial to accident prevention and risk reduction. Simultaneously, it is imperative to elevate safety awareness and prioritize safety management practices to achieve a secure environment for LNG storage.
1. Analyzing the Fundamental Characteristics of Liquefied Natural Gas
Liquefied natural gas primarily comprises methane, along with small amounts of nitrogen, propane, and ethane. The specific composition and proportions of LNG can vary among different production facilities. While industry standards stipulate that methane content should not fall below 76%, LNG is not pure methane. To comprehend LNG thoroughly, it is essential to analyze its characteristics in production and storage, employing computer-related software for a more detailed understanding. Typically stored in insulated storage tanks or underground gas storage tanks, LNG storage incurs specific costs, necessitating stringent safety management during the storage process.
2. Analysis of Risk Factors in LNG Storage
Liquefied natural gas (LNG) is typically stored in double-layer cryogenic storage tanks. LNG, colorless and tasteless, is flammable and prone to vaporization.
(1) Temperature Influence
Temperature significantly impacts LNG. Elevated peripheral temperatures lead to increased pressure within the tank, raising the likelihood of LNG explosions and potential gas leakage. The leaked natural gas rapidly vaporizes, forming an easily combustible gas when combined with air. In the presence of an ignition source, a severe explosion accident can occur, resulting in casualties and economic losses.
(2) Storage Tank Impact
During the storage of liquefied gas, the storage tank itself can introduce risk factors. Loose or malfunctioning grounding devices in the storage tank can cause static electricity buildup, leading to discharges that affect LNG. In the event of a leak, explosions and fires may ensue. Additionally, if the tank wall exceeds its actual service life, corrosion may occur, reducing thickness and compromising anti-corrosion performance, making leaks more likely. The absence or malfunction of pressure gauges weakens the staff's ability to monitor real-time air pressure within the storage tank, hindering their ability to assess the impact of external temperature changes. This lack of information increases the overall risk.
(3) Storage Area Impact
Storage processes are susceptible to risk factors influenced by the storage area. Related factors include:
Inadequate protective walls in the storage area make it challenging to effectively mitigate fire or explosion consequences in the event of natural gas leakage, leading to preventable losses.
Insufficient basic equipment or poorly designed support structures in the storage tank can result in deformation and damage during storage. Tank toppling increases potential losses, elevating the risk.
The explosion-proof area serves as a safety defense line. Incomplete equipment, unreasonable design, or the absence of necessary explosion-proof tools diminish the area's effectiveness, heightening storage risks.
3. Safe Storage Practices for Liquefied Natural Gas
(1) Enhanced Stratified Detection in LNG Storage Tanks
Detecting and preventing the stratification of liquefied natural gas (LNG) in storage tanks is crucial to avoiding potential hazards. The stratification of natural gas is a leading cause of LNG rollovers, making it essential to conduct thorough detection and implement corresponding preventive measures. One effective method involves strategically placing temperature measuring points at specific heights within the storage tank, ensuring vertical spacing is less than two meters. Typically, a temperature difference of approximately 14°C signals the risk of rollovers. Additionally, detecting density differences between newly injected LNG and the gas already present in the tank, or assessing the calorific value disparity between them, aids in identifying potential rollover risks.
(2) Prevention and Control of LNG Stratification and Rollovers
During the LNG injection process into storage tanks, the injection method plays a significant role in preventing stratification or rollovers. LNG can be injected directly from the upper nozzle or from the bottom through a pipe inserted from the top. The choice of injection method depends on the specific gravity of natural gas. To prevent stratification or tumbling, heavy natural gas is typically injected from above, while lighter natural gas is injected from below. Utilizing the low-pressure pump of the LNG system to circulate gas within the tank, either in the upper or lower part, is an effective strategy to prevent stratification or rollovers. Installing a ring-mounted nozzle at the tank's top allows for precooling using a small amount of LNG before actual filling, ensuring high safety standards by minimizing stress and excessive evaporation during the filling process.
(3) Implementation of Corresponding Safety Measures
Personnel involved in LNG storage must possess a deep understanding of LNG characteristics and be aware of potential risk factors. Scientific and rational storage practices, considering specific storage conditions, involve setting appropriate temperature, flow rate, and pressure parameters. Adding alarm devices for high temperature and high pressure enhances inspection and supervision within the storage tank, ensuring equipment and pipelines remain in optimal condition. Regular checks of LNG tanks should be conducted to verify the proper installation of instruments, alarm devices, and grounding devices, thereby ensuring safe storage and minimizing accidents associated with tank-related factors.
Conclusion
The storage of liquefied natural gas (LNG) involves numerous safety considerations, emphasizing the need for a thorough analysis of various risk factors. Enhancing professionalism and standardizing storage procedures are essential steps in minimizing storage-related risks. Implementing tailored safety measures is crucial to accident prevention and risk reduction. Simultaneously, it is imperative to elevate safety awareness and prioritize safety management practices to achieve a secure environment for LNG storage.
