New approach for asset management in District Heating (DH) networks

Rehabilitation and renovation of district heating networks are mainly based on an event-based maintenance strategy. This means reactive removal of failures and damages and this also describes the uncertainties in the field of accurate lifetime assessment of district heating networks. However, utilities need evaluated estimation of the serviceability of the networks to define the best moment for reinvestment. Interval-based and condition-based lifetime assessment is used by utilities for lifetime assessment e.g. in the branch of sewer and drinking water-networks. First developments can be observed in the transfer of existing decision making tools from other branches to district heating branch. Nevertheless there are several important differences to be taken to account when lifetime assessment is carried out for district heating networks. On the one hand, inspection methodologies from other networks are not transferable because of temperature and pressure loads in DH-networks. Thus condition-based lifetime assessment needs another concept. On the other hand ageing of DH-networks highly depends on the used pipe system and the operation conditions. The paper presents a new interdisciplinary approach for asset management in DH-networks that was developed by the authors. Different relevant ageing theories for DH-networks were put in order. By a Top-down and Bottom-Up approach these theories are characterized and set in relationship to each other. A first outlook for the next steps to activate these different theories mutually is given, that will make a sustainable rehabilitation planning possible and will lead to new business opportunities in the future. (C) 2017 Published by Elsevier Ltd.