District heating in Chile and advances in the investigation on soil-pipe interactions in district heating networks

Abstract

The high level of air pollution in the cities of central and southern Chile, largely due to the burning of firewood, causes serious damage to people’s health, felling of native forests, house fires, and people’s deaths. An alternative that has been working for more than 100 years in the northern hemisphere is district heating. In Chile, there are two district heating systems operating for several decades and in recent years small projects have been slowly increasing. It is proposed to promote district heating for a greater number of population, either using industrial energy sources that are wasted or from non-polluting renewable energy sources. Then, the analysis is focused on the buried distribution pipe network in relation to its interaction with the ground related to mechanical and thermal response. These pipes are made of steel, insulated with foam and protected with a plastic jacket. Results of measurements in an instrumented pipe circuit connected to a district heating network in operation are presented. The axial displacements of the pipes in stationary conditions are possible to adequately estimate using the available calculation methodologies. However, steady-state conditions of sudden changes in temperature and pressure are difficult to estimate.