Shuangyashan Prefabricated Directly Buried Thermal insulation pipe picture As the current thermal insulation and waterproofing*** New building materials ， polyurethane The application of hard foam insulation materials in domestic construction industry is still in the initial stage. Fortunately, in order to accelerate the innovation of building insulation materials and promote the promotion and application of polyurethane rigid foam in the field of building energy conservation, the Ministry of Construction door A "polyurethane building energy conservation application and promotion working group" was established to promote the application of polyurethane rigid foam insulation and waterproof materials in the domestic building energy conservation industry.
Improved The Conduit Thermal insulation effect; Due to the application of vacuum, the radiation and convection heat transfer of the pipeline are reduced to a limited extent; The corrosion rate of pipeline is reduced; Keep the inner and outer steel pipes dry; It has the function of leakage early warning for the pipe network; The accident rate of pipe network is reduced.
Prefabricated insulation pipe for directly buried high-temperature steam is a kind of pipe in direct underground burial. It can also be directly buried without concrete structure, that is, the thermal expansion of the working steel pipe is carried out in the outer pipe, which reduces the material cost, shortens the construction date, and ensures the safety of the heating pipe, which can be more widely used safely in different temperature environments, It is especially suitable for high temperature steam pipeline projects. The operating temperature can reach 150 ℃ - 450 ℃. The inner steel pipe shall be coated with two degrees of inorganic zinc rich primer (temperature resistance ≥ 400 ℃). The pipe ends shall be sealed with polyethylene film or three layers of PE cold tape to prevent moisture before installation or water during construction. The insulation material is wrapped with multi-layer staggered joints, which effectively reduces the heat loss. At the same time, the measures to control the surface of the jacket prevent the generation of cold bridges, thus ensuring the temperature control of the anti-corrosion coating of the jacket. The multilayer aluminum foil reflective layer is wrapped with thermal insulation materials, which effectively reduces the heat loss and makes the steam pipeline more economical and reasonable.
Anticorrosion coating and cathodic protection are used for anti-corrosion of outer steel pipe, which can greatly increase the anti-corrosion life. The drainage system is fully enclosed, with flexible layout, reasonable structure, safety and reliability. The moisture exhaust pipe on the steel sleeve can not only discharge the wet gas in time, but also serve as the * * * signal pipe for daily operation. The heat compensation of the pipeline adopts high-quality bellows compensator, which is installed in the casing and made into a direct burial form. There is no need to set up observation wells. The construction operation is convenient and the construction period is short.
Low temperature directly buried prefabricated steam insulation pipe (internal sliding)
Internal sliding insulation structure
1. Inner steel pipe
2. High temperature resistant inorganic zinc rich paint
3. High temperature resistant drag reduction layer
4. Microporous calcium silicate inorganic insulation layer
5. Aluminum foil reflector
6. Polyurethane insulation layer
7. Outer steel pipe or outer protective PE jacket pipe
8. Coat anti-corrosion
The pipe support is used to maintain the concentricity between the inner and outer steel pipes, and the high-temperature fiber felt drag reduction layer is used to form the sliding interface between the steel pipe and calcium silicate insulation material. The difficulty of waterproof and leak resistance is successfully solved by taking advantage of the characteristics of high strength and good sealing performance of the steel sleeve. The inner layer of the insulation material is wrapped on the inner steel pipe with microporous calcium silicate staggered joints, and the gap is filled with high-temperature and high elastic insulation material, The heat loss is effectively reduced. Polyurethane insulation material is selected for outer insulation. With the excellent insulation performance of polyurethane, the surface temperature of the outer layer is controlled below 50 ℃ to protect the anti-corrosion layer and increase the overall life of the pipeline. Thermal insulation measures are taken for the fixed support in the steel pipe to prevent the generation of cold bridge, thus ensuring the control temperature of the anti-corrosion coating (below 50 ℃). Wrapping multilayer aluminum foil reflective layer in the inner insulation material effectively reduces the heat loss and makes the steam pipeline more economical and reasonable.
