Thread Content
Yuxiang Populus 2# Four-in-One Nitric Acid Unit Commissioning – Successful First Start-Up of the Facility. Author/Source: Yuxiang Populus. Date: February 24, 2022. Clicks: 11. On February 15, 2022, with the successful individual commissioning of the turbine, the intensive and organized major maintenance work on the four-in-one unit came to an end. In line with the requirement of \"ensuring safety and completing maintenance work with high quality and in full volume,\" the Equipment Department implemented a series of thorough supporting measures during the maintenance period ； The managers in the nitric acid workshop and those in charge of mechanical, electrical, and instrumentation tasks each took responsibility for their respective areas; they braved hardships and worked tirelessly to assist the technicians from Shaanxi Gas Turbine in carrying out their work, enabling the four-in-one unit and related equipment to undergo their initial trial run and start operating. To ensure the smooth progress of this test run, the Equipment Department coordinated with various units to carry out all the preparatory work for the test thoroughly, ensuring that all debugging and testing tasks were completed on time, that the data was accurate and reliable, and that all parameters were adjusted to their optimal levels. At 10:00 a.m. on February 20, all personnel from the nitric acid workshop and those in charge of mechanical, electrical, and instrumentation systems were present to conduct a thorough safety inspection of the unit prior to starting it up. With the roar of steam being released, the four-in-one unit began to spin up. Next to the DCS console in the nitric acid workshop’s control room, technicians from Shaanxi Gear Group and other professional managers watched the screens closely. As commands were given via walkie-talkies, the unit’s speed increased gradually to 500, 1000, 4800, 7800, 8271, and 8600 rpm. There were no abnormal fluctuations in the unit’s vibration levels or bearing temperatures at any of these stages, and all indicators were within normal ranges. By 4:00 p.m., the unit was successfully started up and put into operation. On February 21, the four-in-one unit was operated at a speed of 9,100 r/min to evaluate its energy efficiency; the load reached 70,540 Nm3/h. The vibration levels of the unit and the temperatures of the bearing shells were all within normal ranges. A 72-hour performance test of the unit was conducted simultaneously. On February 22, the Equipment Department organized a technical exchange between the process workshop and professionals in mechanical, electrical, and instrumentation fields and Shaanxi Blower technicians. The discussion covered various aspects such as the operation, commissioning, and maintenance of the units. The Shaanxi Blower technicians provided detailed explanations regarding precautions for starting and shutting down the units, key points to pay attention to during daily operations, as well as thorough guidance on routine maintenance. Thanks to their insights, the process workshop and the maintenance workshops were able to refine and adjust their daily operating procedures for the four-in-one units; moreover, optimization methods and suggestions were put forward to address common issues encountered during regular maintenance of these units. At present, the defects and various safety hazards existing in the unit have been effectively eliminated. As a result, the operating efficiency of the unit has improved, laying a solid foundation for the safe and stable operation of the nitric acid plant.