In the field of cryogenic insulation, with the expanding application of energy sources such as liquefied natural gas (LNG) and liquefied petroleum gas (LPG), the requirements for insulation materials are becoming increasingly stringent. LNG elastic felt and aerogel are currently the two most commonly used types of cryogenic insulation materials, each exhibiting distinct characteristics in cryogenic systems. This article will compare LNG elastic felt and aerogel in terms of material structure, insulation performance, fire resistance, and applicable scenarios to help engineers select materials based on their needs.

I. Differences in Material Structure and Basic Properties

1. Material Structure of LNG Elastic Felt

LNG elastic felt is a high-efficiency cryogenic insulation material with a composite elastic structure. Its core material is a flexible insulation layer, typically made by mixing polyurethane, rubber, and other synthetic materials with other inorganic materials. Its internal microporous structure gives it extremely low thermal conductivity and excellent resistance to cold shrinkage, making it particularly suitable for covering cryogenic pipelines and equipment.

2. Material Structure of Aerogel

Aerogel is an ultralight insulation material made of inorganic materials such as silica. Its internal structure is a nanoscale porous structure with extremely high porosity, making air almost impossible to flow through. Aerogels offer superior insulation due to their extremely low thermal conductivity and extremely thin thickness, and are typically used in high-end projects requiring ultra-high performance insulation.

II. Comparison of Insulation Performance

1. Difference in Thermal Conductivity

LNG Elastic Felt: Thermal conductivity typically ranges from 0.018 to 0.023 W/(m·K), providing excellent insulation and significantly reducing heat loss even with a thin layer.

Aerogel: Extremely low thermal conductivity, typically 0.018 W/(m·K), its insulation performance far surpasses that of traditional insulation materials. Even at extremely thin layers, aerogel provides extremely high thermal resistance.

In terms of insulation efficiency, aerogel is superior at extremely thin thicknesses, while LNG elastic felt, although possessing good insulation performance, has relatively lower performance at the same thickness.

III. Applicable Scenarios and Construction Ease

1. LNG Elastic Felt Application Scenarios

LNG elastic felt is mainly used in the following cryogenic systems:

Cryogenic pipeline insulation

LNG storage tanks and transportation systems

Cooling systems and heat exchange equipment

The construction process of LNG elastic felt is relatively simple. It has high flexibility and can adapt to the installation of complex parts such as pipelines and elbows, making it particularly suitable for equipment surface and pipeline insulation.

2. Aerogel Application Scenarios

Aerogel is mainly used for:

High-performance cryogenic insulation

Equipment protection under extreme temperature conditions

Systems requiring ultra-thin insulation

Aerogel is often used in special applications such as aerospace and petrochemical industries, especially suitable for scenarios requiring extremely high thermal insulation effects with ultra-thin insulation layers. However, due to the rigidity and fragility of aerogel, its construction requirements are high, and it usually needs to be used in conjunction with other materials.

IV. Differences in Fire Resistance and Safety

1. Fire Resistance of LNG Elastic Felt

LNG elastic felt itself has good fire resistance. It typically uses fire-retardant additives to effectively slow the spread of flames and meet fire resistance requirements in low-temperature environments.

2. Fire Resistance of Aerogel

Aerogel, being an inorganic material, possesses excellent high-temperature resistance and fire resistance. In high-temperature environments, aerogel maintains structural stability, does not burn or melt, and has strong fire resistance.

Overall, aerogel exhibits superior fire resistance in extremely high-temperature environments, making it suitable for applications requiring extreme high-temperature resistance.

V. Comparison of Cold Shrinkage Resistance

LNG Elastic Felt: Possesses excellent cold shrinkage resistance, capable of withstanding temperature differences in low-temperature environments, maintaining insulation performance and shape stability.

Aerogel: Aerogel has poor cold shrinkage resistance and typically needs to be used in conjunction with other flexible materials in low-temperature environments to avoid shrinkage problems caused by temperature differences.

Under extremely low temperatures and large temperature differences, LNG elastic felt exhibits more stable resistance to cold shrinkage than aerogel.

VI. Economic Efficiency and Long-Term Benefit Analysis

1. Economic Efficiency of LNG Elastic Felt

LNG elastic felt has relatively low initial investment, is easy to install, and has a short maintenance cycle, offering good cost-effectiveness. In conventional cryogenic insulation projects, LNG elastic felt can achieve a good balance between energy saving and low cost.

2. Economic Efficiency of Aerogel

Aerogel has higher initial costs and its installation is more complex, requiring the use of other materials to ensure construction quality. However, the ultra-high insulation performance of aerogel can reduce energy consumption during long-term operation, making it particularly suitable for projects with extremely high energy-saving requirements, resulting in long-term economic benefits.

In summary, the main differences between LNG elastic felt and aerogel in cryogenic systems lie in their insulation performance, construction adaptability, durability, and cost-effectiveness:

Aerogel: Offers ultra-thin, highly efficient insulation, suitable for high-end, extreme temperature applications such as high-energy-efficiency systems and aerospace. It provides significant long-term energy savings, but initial investment is higher and construction is more complex.

LNG elastic felt: Offers lower initial investment and greater construction flexibility, suitable for most cryogenic insulation systems, especially offering better cost-effectiveness in pipeline and equipment insulation.

When selecting suitable cryogenic insulation materials, engineers need to make a scientific decision based on specific project requirements, budget, construction conditions, and other factors.