Abstract: Hydrocracking plays a pivotal role in resolving the acute contradiction between the increasingly heavier and inferior quality of crude oil and the lighter product slate. Leakage in hydrocracking high-pressure air coolers is one of the major challenges to the long-cycle operation, quality improvement and efficiency enhancement of hydrocracking units, and ranks among the top five issues constraining the "five-year turnaround" long-cycle operation. Traditional leak detection methods are slow to respond, making it difficult to promptly detect minor initial leaks. They cannot visually locate leakage points and fail to provide early warning. This paper presents the development of an online monitoring system for acoustic imaging of high-pressure air cooler leakage based on acoustic imaging technology. The system employs a microphone array to capture abnormal sound source signals, and achieves acoustic imaging localization of leakage points and visualized tiered alarming through diagonal loading beamforming algorithm, acousto-optic fusion technology and leakage risk classification algorithm. Experimental bench tests and field tests have validated that the system is capable of leak localization, visual display and tiered alarming in complex noise environments, achieving an alarm and location accuracy of no less than 90% and exhibiting favorable real-time responsiveness, robustness, and engineering applicability.

Key words: hydrocracking unitlhigh-pressure air coolerlleak detectionlacoustic imaginglleak localizationlonline monitoringlvideo surveillance