Temperature flexible operation of district heating with booster heat pumps – Improving efficiency of existing networks

This paper illustrates a new approach for decarbonizing existing district heating networks by introducing Temperature Flexible District Heating Networks (TFDHs) using decentralized booster heat pumps. A rule-based control concept is presented to effectively manage the varying temperatures within the network. Based on an annual simulation, the optimal heat supply for TFDHs is determined and compared with simulated data of 3^rd and 5^th Generation district heating networks using the Levelized Costs Of Heat (LCOH) as a key performance indicator. The results of the calculations reveal a high decarbonization potential in transforming existing heat networks into temperature flexible heat networks, depending on the fuel source. TFDHs get economical, if the investment costs of the decentralized generation technology are reduced by 10 % and the natural gas price increases by 1 €ct/kWh.