Abstract
Waste heat recovery is one of the key elements at the basis of district heating sustainability.
The available waste heat temperature can however strongly affect the technical
implementation and the performance of the resulting system.
This contribution focuses on the recovery of low-temperature waste heat in an existing
relatively high-temperature network. The considered waste heat source is modelled according
to the simplified behaviour of a data centre, with rather continuous availability, but
non-negligible fluctuations both in power and temperature. The analysis is applied to a case
study in a subnetwork of Aalborg district heating, where loads are partially aggregated and
approximated, though real pipe data are used. The amount and temperature of the recovered
waste heat are parametrically varied within the constraints given by the existing pipe network,
in order to understand the achievable techno-economic performance of the system. This
variability can be related to the details of the actual heat recovery solution, ranging from direct
heat exchange to indirect recovery through a heat pump.
The present work is part of the LIFE4HeatRecovery project, funded by the LIFE Programme of
the European Union under contract number LIFE17 CCM/IT/000085