In recent years, silica aerogel insulation materials have gradually developed, and silica aerogel composite insulation felts have gradually replaced traditional insulation materials as a new type of insulation material used in the insulation industry. Silica aerogel composite thermal insulation felt has broad application prospects in airlines, engineering construction, chemical pipelines and other industries, so it has become the key product research and development target of aerogel polymer materials all over the world.

The so-called silica aerogel composite insulation felt is a composite material of silica aerogel and glass fiber felt, that is, by configuring a solution, the sol-gel process is combined with the glass fiber felt, and then it is formed by microwave heating and aging. Finally, a SiO₂ aerogel composite insulation felt product is formed through a supercritical drying process.

Silica aerogel composite insulation felt has excellent thermal insulation performance. The same is to play the "down jacket" performance, the new material of silica aerogel composite thermal insulation felt, this "new down jacket" has better thermal insulation performance than the traditional material such as aluminum silicate cotton. The average thermal insulation index at natural indoor temperature is 0.011-0.018W/(m·K). With the increase of heating temperature, its thermal conductivity increases, but the thermal conductivity of aluminum silicate wool is significantly larger than that of aerogel. felt. And wearing silica aerogel composite insulation felt no longer needs to wear a layer of raincoat like aluminum silicate cotton. Because the silica aerogel composite insulation felt is absolutely hydrophobic, the hydrophobic rate can reach 99%, which can effectively prevent water from entering the pipeline and equipment. Aluminum silicate wool is a water-absorbing material, and it must be waterproof and isolated in practical application projects. The "new down jacket" belongs to the A1 fire rating, which can withstand the burning of the flame at a high temperature for a long time, and the service life can reach 20 years. With the increase of the service life (usually 2 to 5 years) of "traditional down jackets", the internal aging and pulverization are very serious, and the thermal insulation performance will decrease year by year. It is worth noting that the "new down jacket" does not release any gas or organic compounds in a high temperature environment, and is an environmentally friendly clothing.

In order to more intuitively see the advantages of aerogel composite insulation felt in high-temperature pipeline energy-saving experiments, in June 2021, we will use the new thermal insulation and energy-saving material aerogel blanket to conduct pilot tests, replacing some aluminum silicate wool materials for thermal insulation and energy-saving tests. . By comparing the differences in experimental data such as surface temperature, thermal imaging uniformity, and heat flux density between SiO₂ aerogel felt and aluminum silicate wool material, more energy-saving thermal insulation materials were screened out. The test implementation standard SY/T 6421-1999 "Regulations on Heat Dissipation Loss of Equipment and Pipelines" and GB/T 17357-2008 "Spot Heat Flow Meter Method and Surface Humidity Method for On-site Measurement of Heat Dissipation Loss of Insulation Layer Surface of Equipment and Pipelines", select some heat transfer oils A pilot test was carried out on the pipeline to detect the surface temperature and heat flux density of the two thermal insulation materials. The experimental equipment includes JTDL-4 heat flow meter, WRNK-187/104M thermocouple, EM 1100 temperature measuring gun, DS-2 TPH 10-3-AUF Hikvision thermal imager.

The experiment compared 5 layers of silica aerogel felt and 3 layers of aluminum silicate wool heated at high temperature, the former has better thermal insulation effect. As the heating temperature increases, the surface temperature of the silica aerogel felt also increases, and the difference between the surface temperature changes is not large. When the temperature is 430 °C, the surface temperature is about 44 °C. The heat flux density of SiO₂ aerogel felt and aluminum silicate wool is increasing, but the change of aluminum silicate wool is more severe, and the heat flux density fluctuates greatly. The heat flux density of the aerogel felt is only 172W/㎡ when the temperature is 422℃. The surface temperature of the aluminum silicate wool and the silica aerogel felt is about 37°C; on the whole, it is observed that the heat distribution of the aluminum silicate wool is uneven, and there are cracks on the surface, which are bundled with iron wires; while the aerogel felt The thermal insulation effect is clear at a glance, and the thermal insulation performance is very uniform, which can effectively reduce the loss of heat.

At the same time, the boiler insulation project uses silica aerogel composite insulation felt to conduct pilot experiments on some boiler pipes. When aluminum silicate wool is insulated, its surface temperature is too high, and the surface heat flux density is too large, resulting in too high indoor temperature (up to 53 ℃), which is very unfavorable for engineering personnel activities, accelerates equipment aging, and reduces service life. According to the existing working conditions, the SiO₂ aerogel felt is used for overall insulation, and the indoor temperature can be maintained at about 39 °C, which greatly reduces the indoor temperature.

Overall, silica aerogel composite thermal insulation felt has a unique three-dimensional nano-network structure, which is unique in the field of thermal insulation and has great potential, which will be a huge change in the field of thermal insulation in my country and even the world.