A direct-buried prefabricated heat-insulating high-temperature hot water pipe and its production method

Abstract

The invention relates to the field of polyurethane foaming plastic prefabricated directly buried heat-insulation tubes with high-density polyethylene outer protecting tubes, in particular to a directly buried prefabricated heat-insulation high-temperature hot water tube and a production method thereof. The directly buried prefabricated heat-insulation high-temperature hot water tube comprises a working steel tube, a heat-insulation layer and an outer protecting tube, wherein the heat-insulation layer is arranged between the working steel tube and the outer protecting tube; and thermal contraction sealing end caps wrap two end surfaces of the outer protecting tube and two end surfaces of the heat-insulation layer. The directly buried prefabricated heat-insulation high-temperature hot water tube is characterized in that a galvanized steel wire netting layer and a smooth-surface aluminum plate are sequentially arranged between the working steel tube and the heat-insulation layer from inside to outside, and guiding positioning rings are respectively arranged at two ends of the galvanized steel wire netting layer. Compared with the prior art, the directly buried prefabricated heat-insulation high-temperature hot water tube has the advantages that an inner-layer temperature-reduction heat-insulation structure consisting of an air heat-insulation layer and a reflecting heat-insulation layer is formed, the interface temperature of the inner surface of the polyurethane heat-insulation layer of the high-temperature medium pipe with the designed running temperature ranging from 120 DEG C to 150 DEG C can be reduced to the temperature below 120 DEG C, damage due to carbonization of a polyurethane material is prevented, and long-time safe and stable running of the high-temperature hot water tube is guaranteed.

Description

technical field [0001] The invention relates to the field of prefabricated direct-buried thermal insulation pipes of high-density polyethylene outer protection pipe polyurethane foam plastics meeting the standards of CJ / T114-2000 or GB / T2 047-2012, in particular to a direct-buried prefabricated thermal insulation high-temperature hot water pipe and its method of production. Background technique [0002] At present, for the central heating and hot water pipelines with operating temperature not higher than 120°C and peak temperature not higher than 140°C in the project, high-density polyethylene that meets the CJ / T114-2000 or GB / T2 047-2012 standard is used. The outer protection pipe is a prefabricated direct-buried insulation pipe made of polyurethane foam. Due to the expansion of urban construction, the load of the heating pipe network is gradually increasing, and the heating capacity of the original pipeline is increasingly unable to meet the heating requirements of reside...

AI Technical Summary

Problems solved by technology

Due to the expansion of urban construction, the load of the heating pipe network is gradually increasing, and the heating capacity of the original pipeline is increasingly unable to meet the heating requirements of residents in winter. However, in many cases, due to the unsatisfactory temperature resistance of the original pipeline polyurethane insulation layer, it still cannot be improved. Problems such as operating parameters, heating not up to standard, etc. are still not resolved

[0003] For new pipelines, they may face the same situation of increasing heat load in the future. Therefore, during pipeline construction, even if the design operating temperature is below 120°C, it is still necessary to increase the temperature parameters in the selection of pipeline materials to meet the increase in the future. The possibility of thermal load reservation, which requires the selection of thermal insulation pipes that can operate reliably in the temperature range below 150°C for a long time when constructing central heating pipelines, but at present, there are basically no mature products that meet this requirement in China

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