Justifying the parameters of compensation of temperature extensions of heat network pipelines

Abstract

Problem. Influence of temperature of editing and material of leading pipe of the preliminary isolated hot-water system is set on the size of distance between non-permanent scrays and rule-making in relation to determination of size of maximal distance of placing of scrays on the hot-water system, that determination of their necessary amount. Goal. The purpose of the work is to study the influence of the installation temperature and the material of the conductive pipe of the pre-insulated heat pipe on the distance between the disposable compensators of the temperature elongation of the heat pipe. Method. Preliminary stretching of the heat pipe can be done mechanically or thermally. Since mechanical stretching for the construction of pre-insulated pipelines is very difficult to perform (although it is done), so-called thermal stretching is used in practice - preheating of pipelines. The essence of this method is that the pipeline is heated to an average temperature between the installation temperature and the maximum operating temperature of the heat carrier before it is backfilled. Results. An increase in the distance between one-time compensators for thermal expansion of the heat pipe (reduction in their number) is possible under the conditions of an increase in the temperature of the heat network installation (calculations showed that when the installation temperature changes from 0 °С to +20 °С, the maximum distance between compensators increases by 2.33 times (instead of 10.3 m, received 24 m), therefore the required number of compensators will decrease). Scientific novelty. The influence of the installation temperature and the material of the conductive pipe of the pre-insulated heat pipe on the distance between disposable compensators has been established, and recommendations have been made for determining the maximum distance of placing compensators on the heat pipe, that is, determining their required number. Practical significance. The use of steels with higher values of allowable stresses (calculations showed that replacing St.10 steel with an alloyed one, with an increase in allowable stresses by 1.42 times, increases the maximum distance between disposable compensators by 5.1 times, which also significantly reduces their number on the heat pipe).