Failure consequence evaluation of uncontrollable district heating network

The control system of some existing district heating networks (DHNs) is not sufficient to handle urgent failure scenarios, which cannot make timely and effective responses within a short period after failures. The failure of this uncontrollable DHN will cause more severe consequences. To search critical areas for protection, this study proposed a failure consequence evaluation model. Then, the calculation model of each evaluation index was established based on graph theory, information entropy and safety economics considering topology, function, casualty and economy losses. Spearman correlation coefficient was applied to analyze the correlation of various evaluation indexes and we studied the applicability of each index. Finally, we simulated a single-heat-source DHN case for failure consequences. According to the simulation results, the critical isolation areas are effectively-identified, and the results indicate the applicability of the evaluation model. Moreover, the factors affecting the failure consequences were explored through sensitivity analysis. Among the three sensitive factors of maintenance time, unit price of electricity, water and heat, compensation coefficient, the maintenance time has the most significant influence on failure consequences. When the maintenance time reduces by 20%, the property economic loss in each isolation area reduces by 8.5–29.28%.