Energetic and Exergetic Analysis for Reconstruction of aDirect District Heating Substation

Abstract

Different concepts of direct district heating thermal substations are analysed for a building that should implement energy efficiency measures. These measures should reduce the installed heating capacity for 45.3 %. The building, connected to a small district heating network, has a radiator central heating system equipped with thermostatic valves. These valves are not compatible with the present substation, which is in a poor condition and which is designed for constant water flow with variable supply temperature. A thermal substation is a part of a network and the network should be designed hierarchically. A direct substation without temperature control (one level of district heating supply temperature control) could be implemented if all buildings in the system are of the same class of energy efficiency. Oppositely, a substation with an additional control loop should be applied.