Establishing the optimal solution for retrofit of district heating networks. Case study

Modernization of district heating systems is part of European energy policies. The European Commission allocated financial funds for this purpose and a boost of investments can be noticed in Romania, during last years. Identification of the best retrofit solution both from economical and technical point of view is an important target under such conditions. The paper presents an analysis of four scenarios for the retrofit of district heating distribution networks. Each scenario is based on a different type of pre-insulated system: standard pre-insulated steel pipes, double pre-insulated steel pipes, standard pre-insulated PE-X pipes and double pre-insulated PE-X pipes. The pressure losses, the heat losses, the costs of investments and the cost of heat losses during the lifetime of the system were taken into consideration in order to establish the optimal solution.