Designing District Heating Systems for an Improved Economic Efficiency:A Case Study of a Renewable Rural District Heating Network

摘要

In the design phase of district heating networks many parameters that determine the economic efficiency of the network must be chosen. This contribution investigates the economic effects of the choice of the piping system (single or twin pipes), the maximum specific pressure drop, and the return temperature for a rural district heating network. The economic analysis takes costs for network construction and maintenance, heat losses and pump energy into account. The results show that the design variant using twin pipes, pipe dimensioning to 250 Pa/m and network temperatures of 80°C flow and 45°C return is most cost efficient, with heat distribution costs of 3.7 €ct/kWh. This is a cost reduction of 20 % in comparison to the reference variant with single pipes, pipe dimensioning to 120 Pa/m and network temperatures of 80°C flow and 60°C return.