[Haichuan’s Lessons from Others] “Proactive prevention” through systematic technical upgrades to chillers successfully overcomes the challenges posed by high temperatures during summer operations

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On August 29, good news came from the third acrylonitrile workshop of Jilin Petrochemical Company’s acrylonitrile plant: following systematic technical upgrades, the chiller on Line B of the third acrylonitrile unit successfully overcame the challenges posed by high temperatures during summer. Multiple operating parameters of this unit reached their best levels in recent years, achieving the finest condition since it was put into operation in 2010. “With only 5,000 yuan spent on materials and renovation costs, this improvement ensured the stable operation of the compressor for 48,000 hours and reduced the need for scheduled maintenance. It is estimated that costs related to construction and spare parts were saved by around 500,000 yuan, thus achieving the goal of efficient operation with minimal investment – a true example of ‘low cost, high returns’. ”The project leader said. As the core equipment of the acrylonitrile plant, the chiller plays a vital role in supplying chilled brine to the entire facility; its operating condition directly determines whether the plant can operate at full capacity throughout the summer. However, in recent years, this equipment has been facing issues such as high vibration levels, deviations in rotational speed settings, and inconsistent liquid level readings, which not only affect operational efficiency but also pose safety risks. In the face of this challenge, the factory assembled its technical experts and worked together with equipment manufacturers to form a dedicated task force that carried out a series of precise and efficient technical efforts, thereby promoting a shift in equipment management from \"reactive maintenance\" to \"proactive prevention\". During the detailed disassembly and repair of the chiller compressor, the troubleshooting team found that the retaining rings of the second and third stage balance tubes were structurally damaged, with significant wear on their outer surfaces, which severely hindered the stable operation of the unit. To address this underlying issue, the team developed an innovative modification plan: by adjusting the structure and dimensions of the retaining ring, as well as increasing the outer diameter of the balance tube, it was possible to effectively suppress the radial movement of the balance tube under extreme operating conditions ； At the same time, increasing the length of the balance tube reduced axial movement, thereby eliminating the risk of vibration in the unit caused by damage to the balance tube. Key parameters such as unit vibration and displacement decreased significantly, and the readings from the main vibration monitoring point XE-403 also showed a steady decline, completely eliminating the risk of vibration alarms. At the same time, the project also enables remote monitoring of three key liquid levels, including those of the evaporator, allowing operators to monitor the real-time operating status of the unit; this significantly improves the accuracy of system control as well as the ability to respond to emergencies.