\"2017 Work Summary: Maintenance Equipment Management for Cracking Units\" (Statistics completed)

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bg2.png The main tasks for the hydrocracking unit in 2017 were the shutdown for maintenance of the unit and issues related to its long-term operation thereafter. In 2017, the hydrocracking unit operated smoothly overall, with no unplanned shutdowns. The specific tasks are as follows: 1. Carry out detailed work to complete the maintenance plan and tasks for the facility for the year 2017, and contribute to the preparation of the maintenance plan for shutting down the facility in 2017. To make the overhaul plan more comprehensive and ensure nothing is overlooked, past experience with shutdowns for maintenance was taken into account, reasonable suggestions were widely sought, and these suggestions were discussed item by item with workers, technicians, and team leaders, followed by project formulation and evaluation. By reviewing the work notes and compiling the issues recorded on a daily basis, discussions were held with the fitter’s workshop to properly arrange them within the maintenance plan. This included inspections of the feed pump gearbox that were not part of the original plan; during these inspections, it was found that the shaft coupling of the pump was damaged and that the bevel gears were dirty. After repeated reviews and multiple adjustments, with meticulous attention to detail, the preparation of the plant maintenance project documents was completed. The hydrocracking unit maintenance projects consist of 16 major categories, which are further divided into 177 sub-items. Among these, there are 2 company-level items, namely the replacement of catalysts in the refining reactor and the cracking reactor, as well as the maintenance of the recycle hydrogen compressor; there are 14 projects at the workshop level. There are 38 projects related to technological upgrades and improvements, of which 6 are aimed at energy conservation and emission reduction, and 2 address safety hazards. The users involved in the maintenance of rotating equipment mainly include: 1. Maintenance of the circulating hydrogen compressor C1001 ； 2. Maintenance of new hydrogen compressors C1002A/B ； 3. Maintenance of feed pump P1001A ； 4. Centrifugal pump maintenance ； 5. Motor maintenance. During the shutdown for maintenance of the equipment, proper supervision of the maintenance work on the large units is necessary; the relevant teams should be coordinated to assist the fitters in their tasks, ensuring that the maintenance of these large units is completed successfully. No abnormalities occurred during the startup process, and the dry gas seal system of the recycle hydrogen compressor as well as the old gas valves of the new hydrogen compressor were promptly sent back to the factory for repair, ensuring that critical components of the unit always had available spare parts. During the major overhaul, assign dedicated personnel to replace the lubricating oil in the unit and clean the lubricating oil tank, to ensure that the unit’s lubricating oil system remains in good condition. Check the condition of the pump’s maintenance work, and promptly flush the bearing housing, replace the lubricating oil as well as the sealing fluid, to ensure that the pump is ready for operation as soon as possible. Also, report any issues found to the fitter’s workshop so that they can be addressed promptly. 2. Adopt a more meticulous approach to improve on-site equipment management; the service life of mechanical equipment depends primarily on three factors: the quality of the equipment itself, operating conditions, and maintenance. When the quality of the equipment is fixed and the range of adjustable operating conditions is very limited, proper maintenance is the only important means to ensure its long-term operation. Lubrication is an important prerequisite and essential condition for the smooth operation of mechanical equipment. Regular lubricant analysis is conducted once a month on the 5 large-scale units in the hydrocracking unit, and any issues identified in the analysis results are promptly analyzed and addressed. To address the issue of water content in the lubricating oil of the hydrogenation feed pump P1001A, an application has been made to add dehydration equipment to ensure proper lubrication. Currently, the motor and level gauge of the dehydration equipment have been repaired, and the filter elements are under order. The lubricant for the pumps is replaced quarterly, and the condition of the compensation oil cups is checked daily; any changes in color or consistency are addressed by replacing the oil promptly. Regularly check the condition of the sealing isolation fluid in Plan53B. The crew is required to strictly control the sealing pressure; when replenishing pressure, operations must be carried out smoothly to reduce the impact of pressure addition on the seal. For the Plan52 sealing system, if an increase or decrease in the level of the lubricant tank is observed, the cause is analyzed; in cases where the rate of change is significant, maintenance is carried out, while in milder cases, the liquid is drained or replenished as appropriate. Additionally, the lubricant with an elevated level is replaced regularly to ensure the reliability and stability of lubrication for the rotating equipment. Lubrication maintenance is carried out quarterly on the air-cooled fans and the backup centrifugal pump motors, while the wear of belts is checked from time to time; in cases of severe wear, they are replaced promptly to ensure optimal air-cooling efficiency. Improve the management of equipment and teams in a more meticulous manner to achieve comprehensive equipment management, thereby fundamentally raising the level of on-site equipment management. 3. Complete all preparatory work in advance and improve basic management by further refining basic management documents such as equipment registers, spare parts registers, and technical archives; meanwhile, gradually implement electronic management of technical archives for units and pump equipment. Electronic technical archives have the advantages of covering comprehensive information and enabling easy retrieval; they can also include materials with large volumes of data such as technical summaries, equipment diagrams, and fault analyses, thus offering the advantage of having all the necessary information at hand for easy reference. Leveraging the advantages of electronic information technology in terms of advancement and intuitiveness, continuous improvements are made to the basic management of equipment, thereby raising the overall level of equipment management. By looking ahead and considering the long term, traditional practices are combined with modern management methods to achieve a complete transformation from traditional to modern equipment management. Thoroughly study the company’s various rules and regulations, and revise and improve the detailed management procedures for the workshop, so as to make workshop management more comprehensive, detailed, and reliable in terms of regulations. 4. Take proactive actions early on to determine the lifespan of equipment; plan equipment maintenance in such a way as to accurately assess equipment lifespan and enable predictive maintenance. Since the beginning of 2015, the hydrocracking unit has been capable of tracking and monitoring the operating status of 42 pumps and motors, with complete records of the operational changes and running time data for each piece of equipment. It enables functions such as automatically detecting changes in the start and stop status of monitored devices, calculating cumulative operating time, analyzing and obtaining associated records of pump switching operations. It features good real-time performance, high reliability, and causes no disruption to various systems. By combining the analysis records of each change in the equipment’s status, accurate data support can be provided for the daily operation of the equipment. The accumulation of data over time serves as a factual basis and scientific foundation for predicting the performance of the equipment and its components, as well as for carrying out preventive maintenance. On the basis of achieving automated statistics for the entire device, manual counting of spare parts’ lifespan is carried out, and detailed statistics on the operating time of each component are collected to enable targeted and comprehensive maintenance. Arrange the maintenance schedules for various units and pumps in a reasonable manner, carrying out these tasks early and thoroughly to ensure that maintenance is carried out in a timely and effective manner. Currently, the 17-year maintenance plan for large-scale units is being prepared. 5. Strive for efficiency and optimization, make full use of resources, and reduce energy consumption; while ensuring the safe and stable operation of the equipment, achieve energy savings and lower consumption, thereby reaching a state of maximum efficiency and optimal performance. Large-scale units such as the cycle hydrogen compressor and the fresh hydrogen compressor in hydrocracking units adjust the amount of circulating water in accordance with the ambient temperature, thereby significantly reducing the consumption of circulating water; this enables adjustment based on actual needs and helps to eliminate waste. Since June 29, the two new hydrogen compressors in the hydrocracking unit have been operating simultaneously. Without affecting the amount of fresh hydrogen, the load of the two compressors is adjusted to enable the stepless control system for the fresh hydrogen compressor to function optimally, thereby achieving energy savings. After the adjustment, the current of the new hydrogen compressor C1002A decreased by about 20A. Based on the production conditions, adjust the frequency converter so that the shaft power of the pump is as close as possible to the actual demand, thereby making better use of the energy-saving advantages of frequency conversion. Check the operating condition of the variable-frequency pump; address any issues found immediately. Once repairs are completed, switch to the alternative system promptly to save electricity. After the device is operating stably, the hydraulic turbine system is put into use, saving over 2 million yuan in electricity costs each year. The 220# lubricating oil used in the oil injection system of the new hydrogen compressor in hydrocracking units has a high grade; it cannot be produced domestically and must be imported, which makes it expensive. Finding a way to save lubricant while ensuring safe operation has become key to reducing the operating costs of new hydrogen compressors. To this end, the workshop implements dynamic monitoring and management of the oiling system, adjusting the amount of oil applied according to temperature changes to keep it within an appropriate range; this allows each machine to save 4–5 barrels of lubricant per year, resulting in cost savings of 80,000–100,000 yuan. Oil quantity reminder cards are also posted on site to enable technicians, operators, and the fitter’s workshop to check and adjust the oil volume.