SA Ras Al Khair O&M Project PMC Test Finished
At local time 16:00 of February 22nd, 2017, the N-1 test for SA Ras Al Khair Project’s 10 GTs, 10 boilers, 5 STs, Doosan’s 8 flashes under full-load operation was finished with the project team’s joint effort and the excellent job won appreciation from the owner and the supervisor.
Ras Al Khair Power and Desalination Plant Project is invested by SWCC of Kingdom of Saudi Arabia and locates at Ras Al Khair industrial park. The unit layout accords to element; the total capacity is 3040MW; there are 6 Blocks composed by 5 SIEMENS 9F combined-cycle units and 1 single-cycle unit and relevant auxiliary equipment with 12 GTs, 10 boilers and 5 STs. There are 8 flashes in the desalination plant and the desalted water is supplied to national living water supply.
The power plant is controlled automatically with APS. PMC includes load control, HP main steam pressure control, MP main steam pressure control and back pressure control. PMC test includes GT trip test, boiler trip test, ST trip test, flash trip test, afterburning trip test and load swing test. PMC test is an important milestone for the power plant to achieve commercial operation.
PMC of Ras Al Khair Plant is designed by SIEMENS and used for automatically regulating and distributing the units’ load, main steam pressure, afterburning load, MP pressure and back pressure, automatically controlling the total net output via element control (including ST load control and ST backpressure control), BMC and PMC, and automatically regulating the whole power plant when N-1 tripped in order to maintain the total net output and reduce the influence to the grid.
However, the logic configuration design of PMC of the project is not perfect with a number of mistakes, and the service provided by SIEMENS is over, so the PMC could not be operated.
During commissioning, Mr. Tian Zhigang, Deputy Commissioning Chief Engineer, carefully checked the logic of PMC, modified the mistakes and initially did the test under operation and achieved success. While the owner required that the test should be carried out under full-load operation of 10GTs, 10 boilers, 5 STs and 8 flashes, so the test was delayed due to unqualified condition.
At the beginning of February, the owner required that the project must finish PMC before February 23rd. Then Mr. Luo Fuchun, Deputy Manager of the O&M Project, Mr. Chen Hao, Manager of Safety Production Department, led Mr. Wang Yongguo, Mr. Feng Hao and Mr. Liu Hao, I&C engineers, immediately started to prepare the test, deeply analyzed the logic, principle and test plan and explained the safety and technology to the operators. When checking the logic, the test team found many mistakes of the logic and then perfected the PMC logic after deep analysis and discussion.
During the test, our team met many problems. On the afternoon of February 20th, when doing the ST trip test, LP and HP main pipes main steam pressure and suddenly lost control, so the technical personnel manually controlled the parameters and avoid 5 steam turbines’ trip. After the failure, the I&C team immediately discussed the reason of the failure and analyzed the logic and control method in the evening. Through two-evening hard working, they finally confirmed the test plan. On the morning of February 22nd, the test team carried out review and test for the plan to insure the feasibility of the plan. Finally, the test was finished successfully with all the qualified parameters.
At 16:00 of February 22nd, 5 N-1 trip tests and load swing test lasting for 3 days were finished successfully ending at the last flash trip test. The owner and the supervisor appreciated our job and the chairman of owner’s project supervision and management committee witnessed the success.
Finishing the PMC N-1 trip tests provides reliable guarantee and condition to commercial operation for the owner. It also shows that the company’s commissioning and O&M team could independently solve the high-level technical problem without external experts. The success saves cost for the parent company, improves the company’s influence and builds firm foundation for developing the market of technical service to the company.