The insulation principle of cryogenic storage tank is as follows:

In the heat insulation engineering, thermal conductivity is less than or equal to 0.2w/ (M - K) material called insulation materials.

The heat insulation materials used in cryogenic vessel such as cryogenic cooler and cryogenic circulator should meet the requirements of the following aspects:

1, the thermal conductivity is small, should be in 0.024-0.139W/ (M. K). Using thermal insulation materials with small thermal conductivity can not only reduce the thickness of insulation layer, but also reduce the size and save investment.

2, the density is small, can make the structure, equipment and pipeline support structure to reduce; and the smaller density of materials within a certain range of thermal conductivity is also small.

3, low water absorption and good water resistance, such as high water absorption, the insulation performance deteriorated. Although the thermal side of the heat insulation structure has moisture proof and vapor isolating layer, the steam permeability resistance of any moisture barrier is not infinite, so it is difficult to avoid the steam entering the heat insulation material completely. The cold side vapor permeability is close to infinity, and water vapor can not be discharged from the cold side. In addition, a small amount of water is not required to decay, not loose, and the mechanical strength does not decrease greatly. Generally, the water absorption rate of thermal insulation material is not more than 5%, and the insulation performance is little after moisture absorption.

4, high mechanical strength, should have certain compressive strength, tensile strength, can withstand a certain mechanical impact. Better dimensional stability. Otherwise, after a period of use, it will break and sink at the bottom of the thermal insulation structure, and destroy the insulation effect of the heat insulation structure.

5, the fire resistance is good, the material itself should be nonflammable or nonflammable. If the material is flammable, it should be self extinguishing.

6, low temperature resistance performance, in the use of low temperature range, the structure does not destroy, does not reduce the mechanical strength, in the cycle of freeze-thaw cycle does not destroy, does not reduce the strength.

7, non-toxic, no odor.

8, durable.

9, can resist or avoid moth eaten, rat bite.

10, easy construction, easy to cut, paste. The environment is acceptable, that is, no damage to the environment or slight damage.

As a matter of fact, the thermal insulation material that meets the above requirements does not exist, and all kinds of thermal insulation materials are superior in some aspects, but on the other hand, they are insufficient. Selection should be based on the use of requirements, insulation structure, materials, technical performance, price and other specific circumstances for a comprehensive analysis, comparison, and then make a choice.