Numerical model of the steam pipeline with thermal insulation

Abstract

Purpose The purpose of this paper is to develop a numerical model of a steam pipeline connecting a boiler with a turbine, with an insulated outer surface. The temperature distribution inside the pipeline wall was compared when was perfectly insulated and when used real insulation on the outside surface. Design/methodology/approach The transient temperature, pressure and velocity of steam in the pipeline were determined using a proposed numerical model with distributed parameters. To calculate the transient temperature of the steam and pipeline wall the finite volume method was used. The energy conservation equations were written for all control area around all the nodes. The heat balance equations are a system of first-order ordinary differential equations with respect to time. The Runge–Kutta method of the fourth-order was used to solve the system of ordinary differential equations of the first-order. Findings The temperature distribution in the pipeline wall and the temperature distribution in wall insulation were presented. Also, the temperature of the steam and pipeline wall as a function of insulation thickness was calculated. Based on the results obtained by the proposed numerical model, thermal stresses at the inner and outer surface of the component were determined. To assess the accuracy of the proposed model, the results were compared to the analytical solution for the steady state. Originality/value The paper presents the results obtained from calculations using a numerical model of the steam pipeline with the actual insulation on the outer surface.