Construction method for prefabricating directly-buried uncompensated centralized heat supply pipeline by electrically preheating

Abstract

The invention relates to a construction method for prefabricating a directly-buried uncompensated centralized heat supply pipeline by electrically preheating. The method comprises the following steps of: (1) grooving, adjusting the coordinate and scale height of the heat supply pipeline, and computing the preheating temperature and the designed elongation of the heat supply pipeline; (2) controlling the sand refilling height at a half to three quarters of the pipeline height H; (3) connecting the same-side end of the heat supply pipeline with preheating equipment through a cable respectively, and short-circuiting the other side of the heat supply pipeline through a cable; (4) arranging temperature sensors on the heat supply pipeline respectively; (5) recording the initial temperature of the heat supply pipeline and the initial position of a measuring point, starting temperature raising, controlling the temperature raising gradient within 1 DEG C per hour, and preserving heat after a preheating temperature is reached; (6) refilling sand into both sides of the heat supply pipeline, tamping, and controlling the preheating temperature within the range of +/-2 DEG C; (7) after the designed elongation is reached, shutting down the preheating equipment; and (8) performing subsequent construction according to the steps (1)-(7). The construction method disclosed by the invention is safe, reliable, easy and practical, is easy for accurately controlling construction equipment, and is consistent with the national policy of energy saving and emission reduction.

Description

technical field [0001] The invention belongs to the field of heating pipelines, in particular to a construction method for electric preheating prefabricated direct-buried central heating pipelines without compensation. Background technique [0002] Direct burial without compensation technology was introduced into my country from Western European countries in the early 1980s. In the early 1980s, the preheating method was mainly hot water preheating. Connect the installed central heating pipe network with the boiler room system, the boiler provides heat energy, and the circulating water pump provides power, so that the system is forced to circulate under mechanical action, so as to heat the installed central heating pipe network and ensure that the system is preheating It will elongate to the design elongation when heated at high temperature. In 2004, my country revised the original "Code for Construction and Acceptance of Urban Heating Pipeline Network Engineering" (CJJ28-89...

AI Technical Summary

Problems solved by technology

First of all, the self-weight of the water increases the friction of the pipeline, which seriously affects the elongation of the system; secondly, the boiler room system requires a lot of space, high energy consumption, long time, and large pollution, so the preheating process must be changed.

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