Linear Finite-Difference Schemes for Energy Transport in District Heating Networks

This study evaluates five representative linear explicit finite difference schemes for solving the energy transport equation in district heating networks (DHN). Specifically for the QUICKEST scheme a robust modification to the original formulation is proposed which overcomes the problem originating from different flow situations at pipe junctions. All methods were put into the versatile state space representation for the purpose of simulating the propagation of two benchmark temperature profiles from the DHN plant to the distant consumers. It is shown that the modified QUICKEST scheme produced the most accurate results at the cost of small overshoots in regions of sharp gradients.