Valve failure detection of the long-distance district heating pipeline by hydraulic oscillation recognition: A numerical approach

The long-distance district heating pipeline (LDHP) system can deliver waste heat from suburban areas to urban areas. Valve-induced hydraulic oscillation caused by valve failure will lead to large fluctuations of pressure, which may also result in pipeline rupture of the LDHP system. Fast and accurate detection of the faulty valve is a necessary measure for efficient repair and adjustment of the LDHP system. In this paper, the hydraulic transient model of the LDHP system based on the distributed parameter method is combined with the Particle Swarm Optimization algorithm to realize fast and accurate detection of the location and status of faulty valve, by recognizing the faulty valve-induced hydraulic oscillation in the LDHP. The effectiveness of the detection algorithm is verified by numerical simulation of a 20 km LDHP system, and the effects of instrumental error and sampling period on the robustness of the algorithm are investigated. Results show that when the sampling period is less than 10 s, the relative errors of the detected location and opening of the faulty valve are less than 8% and 0.1%, respectively. Therefore, the faulty valve-induced hydraulic oscillation in the LDHP can be effectively detected based on the method proposed in this paper.