Application Of Aerogel In Energy Industry
Aerogel's special structure makes aerogels different from the heat insulation of other porous materials. Aerogel composites are made from amorphous silica gel and substrate felt under supercritical conditions. The aerogel can effectively reduce the high brittleness of the aerogels and enhance the valence bond structure between them and become the most promising super thermal insulation materials. Different aerogel composites were prepared according to different temperature. According to strength and softness, the composite products can be divided into two categories, aerogel felt and pneumatic rubber sheet, and the gas rubber sheet is customized. According to the maximum usage temperature, the composite products are divided into 130 kinds of temperature resistance, 650 degrees, 1100 degrees, and 1300 degrees.
According to the properties of aerogel high-temperature felt, the application of products is mainly in the following aspects:
Oil field is a large capacity, and it is also a big energy consumer. The total amount of thermal insulation materials used in petroleum and petrochemical each year accounts for about 1/4 of the total heat preservation material in the country. A large number of pipes and thermal equipment need to be insulated. Petrochemical thermal insulation industry mainly aims at 100~500 high temperature pipeline. The purpose of thermal insulation is to prevent the temperature drop of the medium from affecting transportation or high temperature injury.
The types of materials used in oil pipeline insulation and the thermal conductivity of aerogels are as follows:
|Heat conductivity coefficient mw/m·k||25℃||100 ℃||200 ℃||400 ℃|
|Foam Materials||36||not available||not available||not available|
Under normal circumstances, there is no need for heat preservation, such as gasoline and diesel oil. In special areas, for example, in cold areas, thermal expansion and cold contraction will freeze the pipes, and the finished product pipelines need to be kept warm. Adding new aerogel as a new super thermal insulation material, in oil mining, pipeline, oil refining pipeline insulation, compared with the traditional thermal insulation materials have the following advantages:
|Comparative study||Traditional thermal insulation material||Aerogel thermal insulation material|
|thermal insulation||At room temperature, the thermal conductivity is above 0.036W/mK.
The material has large installation thickness and occupies much space.
The operation effect is poor in narrow space.
|The thermal conductivity of aerogel thermal insulation material at
normal temperature is 0.018 W/mK, which can greatly reduce the
installation thickness of the insulation layer, improve the
installation space and reduce the heat loss effectively, and the
energy saving effect is excellent.
|service life||The traditional insulation material has short service life and needs
to be maintained and replaced frequently. The pipeline has been unable
to meet the design temperature and pressure for the long use of the
internal fluid at the end because of the decrease of thermal insulation
|Aerogel insulation materials have high compressive strength, stable
performance and long service life, usually in more than 10 years.
|designability||The structure of traditional silicate insulation materials is poor in
structure and easy to appear thin and thick.
|Aerogel thermal insulation material is flexible material, and can be
tailored to material and installation according to complex shape,
curvature and space limitation.
|waterproofness||Most of the traditional inorganic materials have no waterproof effect
and are easy to cause pipeline corrosion, which makes the pipeline
unable to guarantee the design pressure requirements.
|Hydrophobic aerogel insulation material has excellent waterproof effect,
and the hydrophobicity rate is over 99%, to prevent and reduce
pipeline corrosion to the maximum extent.
Two. LNG and other deep cold heat preservation
The current situation of LNG insulation
In the construction of LNG projects and other cryogenic projects, cryogenic and ultra-low temperature equipment involves temperatures ranging from -40 to -170 degrees Celsius. The most commonly used cryogenic materials are PUR/PIR, foamed glass, rubber plastic, modified phenolic foam and so on. These materials are compared to the previous perlite materials, which have been greatly improved in terms of performance and construction. The effect of cold preservation is not only related to the efficiency of the whole equipment, but also to the safe production of the plant. Appropriate cooling materials can not only reduce energy consumption and reduce the loss of cooling capacity, but also provide protection for environmental protection requirements, safety production and better efficiency for enterprises. Aerogel insulation material appears to be tailored for this cryogenic insulation and has been widely applied at home and abroad.
Most of the LNG pipeline cooling projects in China are not ideal. The main defects and causes are as follows:
* the thermal insulation performance of traditional materials is very fast, resulting in high maintenance cost.
* traditional materials have poor cold insulation effect and large cold losses, which are likely to cause danger to natural gas or other compressed gas storage and transportation.
* the thickness of traditional material package is large, which brings inconvenience to dense pipeline layout design.
* pipes are easily corroded by dew water due to poor effect of cold insulation layer.
* the cold insulation layer is easily lost because of too much dew.
* the waterproof properties of organic materials can but can not meet the requirements of fire protection.
The benefits of aerogel materials
* the cooling effect is excellent, the thermal conductivity is <0.01W/m.k at ultra-low temperature, the thickness of the cooling layer is greatly reduced and the cooling loss is reduced effectively, which provides optimization for the design of dense pipeline arrangement.
* it has the best low temperature stability. At -200 C, it can maintain cold retention and good flexibility for a long time without cracking.
* excellent dimensional stability. Nano scale special structure can resist internal stress caused by pipeline expansion without setting expansion joints.
* the hydrophobicity of aerogel material is good, it can effectively inhibit water infiltration into the surface of metal pipeline, prevent pipeline corrosion and prevent thermal insulation material from water seepage and reduce the heat preservation effect.
* cutting materials, convenient construction, low maintenance cost.
Compared with the specific properties of the better cold proof materials.
|Aerogel composite blanket||Foamed glass||Foamed PIR
Polycyanic acid polythiocyanate
|heat conductivity coefficient，W/(m•K)||0.010～0.020||0.050～0.080||0.030～0.040|
|Cold insulation thickness||About 1/2||2||1|
|waterproofness||The overall waterproof and hydrophobicity rate is more than 99%.
Nanostructures can effectively resist condensation and frosting.
need for additional
need for additional
|constructability||It can be rolled, shaped, flexible and easy to construct.||Poor, high loss||Ordinary, on-site foaming,
but poor foaming uniformity.
|Ultra-low temperature stability||Excellent, life expectancy 3-5 years.||The stability is general,
and the life span is about 2
|Easy aging, low strength,
poor stability, 6 months
to 1 years to replace.
|reusability||When disassembling and repairing, reusable.||Disassembly is fragile
and cannot be used.
|Disassembly is fragile
and cannot be used.
|other||With the thickness of 1/2, the volume is about 1/3, reducing the
cost of auxiliary materials by 25%, and reducing the difficulty of