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Introduction: Moisture reduction of insulation material insulation effect, insulation material with thermal displacement affected by extrusion insulation balance, become the steam pipeline insulation work in the two major problems. What can be done to improve these problems?
First, the common problems of steam pipeline insulation work
Steam pipeline is the "lifeline" of petrochemical plant, and also an important hub of pipeline for public works. The steam pipeline has the characteristics of large diameter, long distance and high pressure drop and temperature drop. To ensure the operation effect of steam pipeline, pipe insulation is one of the important factors.
Properties of raw materials: There are many kinds of insulation materials, rock wool, glass wool, slag wool, etc., which have experienced market verification. According to the analysis of market research, it shows that the thermal insulation structure made of soft materials like slag wool is easy to sink seriously. This is because the steam pipe will produce water shock and pressure fluctuations, causing the pipeline to vibrate.
External environmental impact: If the insulation material is not placed in a ventilated and dry environment, it may be damp, especially in the humid southern region, the insulation material is easy to absorb moisture in the air. Once the insulation material is damp, its thermal conductivity is likely to rise, reducing the insulation effect of the insulation material. After absorbing moisture, some insulation materials may be powdered when heated.
Pipeline design impact: The displacement of the compensator segment and pipeline due to thermal expansion, equipment interface displacement and thrust. Some pipe sections are not insulated, which will lead to serious heat loss.
The above problems are very common in steam pipe insulation. How to overcome these problems one by one to achieve better insulation effect to help the application of steam pipelines?
Second, the improvement of material selection and environmental conditions
First of all, we start with the problem of material selection.
The above mentioned traditional soft materials will have insufficient moisture absorption, which will affect the service life of thermal insulation materials, and also lead to heat loss. Not only to meet the needs of steam pipe insulation, but also to meet the waterproof and moisture-proof, to ensure the insulation effect and service life; Is there any material that can basically meet the high requirements of steam pipe insulation?
So far, we have learned that there is a correct answer - aerogel composites. In March this year, we learned that Sinopec entered the aerogel circuit, not only as an investor, but also as a client of the industrial chain, affirming the application prospect of aerogel in pipelines.
Moreover, according to the research results published by China Petroleum Pipeline Science and Technology Research Center, the three thermal insulation schemes of steam pipelines are compared in terms of thermal insulation performance, initial investment cost, operation and maintenance cost, and the results show that the aerogel composite products have greater comprehensive advantages than the traditional thermal insulation materials.
The thermal insulation properties of aerogel are beyond doubt. The nanoporous structure of aerogel can effectively prevent air convection, reduce heat radiation and heat conduction, and make it have a lower thermal conductivity. The aerogel material (such as silica aerogel) itself has a high brittleness and is fragile, which is difficult to be directly used in various equipment. In the later stage, people improve their mechanical properties through aerogel material composite fibers, organic compounds and other substrates, and develop into different forms of products suitable for various fields. Pipeline insulation is mostly made of aerogel felt products.
Previously, we made a brief science on the hydrophobic properties of aerogel: The aerogel itself is hydrophilic, but when the aerogel encounters a chemically active substance, it will immediately recombine with the oxygen and hydrogen groups covered on the surface of its structure to form a hydrophobic non-polar group. When 30% of the oxygen and hydrogen groups in the aerogel form hydrophobic groups, it can play a hydrophobic effect.
The second is the storage of thermal insulation materials. Insulation materials should strictly follow the principle of waterproof and moisture-proof from entry to construction. If there is a warehouse, keep the warehouse dry and ventilated; If the stack can only be stacked outdoors, place the bottom of the stack high and cover it with a waterproof cloth to prevent moisture caused by thunderstorms.
Finally, the insulation construction link should be strictly controlled, not perfunctory slack. In fact, the characteristics of the light weight of aerogel felt have created more convenient construction conditions, in addition to a set of standard construction procedures, but also need to check the relevant personnel layer by layer acceptance, to ensure the construction process, the results of the standard