  The 4th generation of district heating systems face a potential problem where
lowered water temperatures lead to higher flow rates, which requires higher
hydraulic capacity in terms of pipe and pump sizes. This increases the effect
of the already existing issue of hydraulic bottlenecks, causing peripheral
units (customers) to experience reduced flow rates. A coordinating control
strategy is presented in this work aimed at reducing the effect of such
bottlenecks on the comfort of customers. This is done by distributing the flow
deficit over many units rather than a few. Previous works mainly focus on
MPC-structured controllers that depend on complex system models and online
optimization techniques. This work proposes a method that requires little
information about models for individual units and minimal IT communication
between control systems. The proposed method is compared with a traditional
control strategy and an optimal baseline in a simulation study. This shows that
the proposed method can decrease the worst case indoor temperature deviations.
