Thermal conductivity is an important parameter to measure the thermal conductivity of materials. For aluminum silicate fiber felt, its thermal conductivity directly determines its thermal insulation performance. The following are the specific effects of thermal conductivity on the properties of aluminum silicate fiber felt:

I. Thermal insulation effect

(1) Advantages of low thermal conductivity

The thermal conductivity of aluminum silicate fiber felt is usually low, ranging from 0.06 W/m·K to 0.18 W/m·K (the specific value depends on density and temperature). Low thermal conductivity means that the material has great resistance to heat transfer and the heat transfer speed through the felt is slow.

For example, in industrial furnaces, when aluminum silicate fiber felt with low thermal conductivity is used as the inner lining, it can effectively prevent the high-temperature heat in the furnace from being transferred to the outside, so that the outer surface temperature of the furnace can be significantly reduced. This not only reduces the heat loss, improves the thermal efficiency of the furnace, but also reduces the safety hazards caused by high temperature on the outer surface of the furnace.

In the application of high-temperature pipeline insulation, aluminum silicate fiber felt with low thermal conductivity can significantly reduce the heat loss of high-temperature medium in the pipeline, maintain the temperature stability of the medium in the pipeline, and at the same time protect the outer layer of the pipeline from high-temperature corrosion and prolong the service life of the pipeline.

(2) disadvantages of high thermal conductivity

If the thermal conductivity of aluminum silicate fiber felt is high, its thermal insulation effect will be greatly reduced. Heat will be quickly transferred through the felt, which will lead to the increase of the external surface temperature of the equipment, which not only increases the energy consumption, but also may increase the ambient temperature around the equipment, affecting the operation of personnel and the normal operation of the equipment.

For example, in some occasions with strict temperature control requirements, such as high-temperature protection of precision instruments or heat-sensitive chemical reaction equipment, fiber felt with high thermal conductivity can not meet the heat insulation requirements, which may lead to equipment damage or process failure.

II. Energy-saving effect

(1) Low thermal conductivity and energy saving

Aluminum silicate fiber felt with low thermal conductivity can significantly reduce heat loss. In industrial production, this means that the consumption of fuel or electricity can be reduced to maintain the high-temperature operation of equipment.

For example, in the heating furnace of metallurgical industry, using aluminum silicate fiber felt with low thermal conductivity as thermal insulation material can reduce the heat loss of furnace body, thus reducing fuel consumption and improving energy utilization efficiency. It is estimated that the decrease of thermal conductivity by 0.02 W/m·K may reduce the energy consumption of furnaces by about 5%-10%.

In the field of architecture, the low thermal conductivity of aluminum silicate fiber felt used for fire doors or firewalls can effectively prevent the heat transfer during fire, reduce the heat loss inside the building, reduce the degree of damage to the building structure by fire, and also reduce the energy waste caused by fire.

(2) High thermal conductivity and energy waste

Aluminum silicate fiber felt with high thermal conductivity will lead to a large amount of heat loss. In order to maintain the normal operating temperature of equipment or system, more energy needs to be consumed to supplement the lost heat.

For example, in high-temperature steam pipeline insulation, if fiber felt with high thermal conductivity is used, steam will lose a lot of heat in the pipeline transmission process, which will lead to the decrease of steam temperature. In order to ensure that the steam temperature at the end of the pipeline meets the process requirements, it is necessary to increase the fuel consumption of the boiler to increase the initial temperature of steam, which will lead to the waste of energy.

III. Equipment Safety

(1) Low thermal conductivity and equipment protection

Aluminum silicate fiber felt with low thermal conductivity can effectively protect equipment from high temperature erosion. In high temperature environment, if the equipment shell or other components are directly exposed to high temperature environment, they may be deformed, damaged or even cause safety accidents due to high temperature.

For example, using aluminum silicate fiber felt with low thermal conductivity as thermal insulation layer on the outside of the furnace body of glass melting furnace can control the external surface temperature of the furnace body within a safe range, prevent the steel structure of the furnace body from softening or deforming due to high temperature, prolong the service life of the furnace body, and ensure the personal safety of operators.

In the engine compartment of an automobile, aluminum silicate fiber felt with low thermal conductivity can isolate the heat generated by the engine in the engine compartment, prevent the heat from being transferred to the cockpit or other sensitive parts, reduce the fire risk and improve the safety of the vehicle.

(2) High thermal conductivity and risk of equipment damage

Aluminum silicate fiber felt with high thermal conductivity can not effectively prevent heat transfer, and the external surface temperature of equipment will rise rapidly, which may lead to equipment shell deformation, seal failure and other problems.

For example, in some high-temperature reactors, if the thermal conductivity of the thermal insulation material is too high, the high temperature of the outer wall of the reactor may lead to cracking of the thermal insulation layer, damage of the sealing gasket, and even abnormal rise of the internal pressure of the reactor, resulting in serious safety accidents such as equipment explosion.

IV. Service life

(1) Low thermal conductivity and long service life

Aluminum silicate fiber felt with low thermal conductivity can reduce the erosion of heat on the felt itself. In high temperature environment, heat has a negative impact on the physical and chemical properties of materials, such as the decrease of fiber felt strength and the acceleration of aging.

For example, in the high-temperature reaction equipment in the chemical industry, aluminum silicate fiber felt with low thermal conductivity is used. Because of its good thermal insulation performance, the internal temperature of the felt is relatively low, and the chemical stability of the fiber felt is higher, so it is not easy to be corroded by corrosive gases at high temperature, thus prolonging the service life of the fiber felt.

From the economic point of view, although the price of aluminum silicate fiber felt with low thermal conductivity may be slightly higher, it is a more economical choice from the long-term use cost because of its long service life and reduced replacement frequency.

(2) High thermal conductivity and shortened life.

Aluminum silicate fiber felt with high thermal conductivity is easily eroded by high temperature environment because of its fast heat transfer and high internal temperature. For example, in a high-temperature furnace, the fiber felt with high thermal conductivity may lead to the aging of the bonding agent between fibers and the decrease of fiber strength due to high temperature, which will eventually lead to the damage of the felt body, loss of heat insulation effect and shortened service life.

V. Environmental adaptability

(1) Low thermal conductivity and environmental friendliness

Aluminum silicate fiber felt with low thermal conductivity not only insulates heat, but also reduces the influence of heat on the surrounding environment. In some occasions that require strict environmental temperature, such as electronic equipment room and precision instrument workshop, the use of fiber felt with low thermal conductivity can effectively prevent the heat generated by equipment operation from overheating the surrounding environment.

For example, in the server room of a data center, the operation of the server will generate a lot of heat. Using aluminum silicate fiber felt with low thermal conductivity as heat insulation material can reduce the heat loss to the computer room, reduce the cooling load of the air conditioning system, save energy, and be beneficial to the stable operation of the equipment.

From the point of view of environmental protection, fiber felt with low thermal conductivity reduces energy consumption and indirectly reduces greenhouse gas emissions, which meets the requirements of sustainable development.

(2) High thermal conductivity and environmental interference

Aluminum silicate fiber felt with high thermal conductivity will lead to a large amount of heat loss to the surrounding environment, which may increase the local environmental temperature, affect the normal operation of other equipment, and even cause discomfort to the working environment of personnel.

For example, in some workshops with dense high-temperature equipment, if the thermal conductivity of thermal insulation materials is too high, the temperature in the workshop may be too high, so it is necessary to increase ventilation or cooling equipment to reduce the ambient temperature, which not only increases the equipment investment and operation cost, but also may have a negative impact on the health and work efficiency of personnel.

To sum up, thermal conductivity is the key factor affecting the performance of aluminum silicate fiber felt. Aluminum silicate fiber felt with low thermal conductivity can significantly improve heat insulation effect, reduce energy consumption, protect equipment safety, prolong service life, and is environmentally friendly. Therefore, in practical application, aluminum silicate fiber felt with low thermal conductivity should be preferred to give full play to its advantages of thermal insulation.