Discrete event simulation for dynamic thermal modelling of district heating pipe

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Volume Title
A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
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Energy, Volume 285
Optimizing district heating (DH) systems in a holistic manner is often impeded by the computational complexities associated with network modeling. This study introduces a novel, efficient and theoretically accurate method for dynamic thermal modelling of DH pipes. The approach is to track water frontiers traveling along the pipe using discrete event simulation (DES) paradigm. As the DES method is based on variable time steps, the computational effort is significantly reduced compared to earlier methods. The proposed model can compute outlet water temperature, temperature profile along the pipe, and heat loss based on variable inlet temperature and flow rate. The DES model was validated by comparison with real measurements of a long DH pipe. Four variants of the model with different temperature profile assumptions and interpolation methods were compared. Numerical results show that the DES model can accurately predict outlet water temperature with a maximum discrepancy of 0.52 °C. The mean error of simulated outlet temperature was −0.01 ± 0.02 °C. Average computation time for 24-h simulation was 59 μs. Overall, this study shows that the DES method is appropriate for variable time step simulation for DH pipe, potentially, for network simulation. Our study may also inspire variable time step implementation in other energy applications.
Funding Information: This study was supported by academy research fellow funding from Research Council of Finland (Funding No. 334205 and 358055 ). Publisher Copyright: © 2023 The Authors
Discrete event simulation, District heat pipe, Dynamic thermal simulation, Heat losses, Lagrangian method, Variable time step
Other note
Xie , Z , Wang , H , Hua , P & Lahdelma , R 2023 , ' Discrete event simulation for dynamic thermal modelling of district heating pipe ' , Energy , vol. 285 , 129523 , pp. 1-11 . https://doi.org/10.1016/j.energy.2023.129523