Automatic Power Plant Startup And Shutdown Technology Research And Its Application Based On Ultra-supercritical Unit Water System

The startup and shutdown control is an automatic control technology, which make the thermal Power Unit operate more accurate, conserve more energy and run more efficient in the process of startup and shutdown. This paper studies steam and water system of 1000 MW ultra-supercritical thermal power units. By analyzing development status and research trends, combined with analyzing the characteristics and difficulties of APS control system, we designed a steam and water system of APS in the 1000 MW ultra-supercritical thermal power units. At the same time, simulation support system(STS) developed by Jade Science and Technology Co., Ltd. and distributed control system(TOP7) developed by Zhejiang Province Electric Power Research Institute serve as a platform. In this paper I designed the overall framework of APS, which puts the Pyramid hierarchical control and the idea of breakpoint as the core, the step sequence of function group and the monitor screen of the subsystem as the key. Finally, by commissioning the unit, we designed the startup and shutdown control system, which is perfect and available. We implemented the group division, designing and building the logic diagram, designing and generating the screen of self start and stop, setting and controlling the analog of water system, and designing reasonable logical for automatically incorporating into the pump and cutting the pump, dry and wet conversion process, which guaranteeing minimum water disturbance and does not occur the phenomenon of alternating between wet and dry state in the process. The control system we designed in this paper can be putted in at any time. Its best feature is the realization of controlling the analog and interface technology. We put the function of analog setpoint, scheduled opening,, and automatic investment in practice. Interface technology can be linked to the entire system and achieved full control. Finally, we debuged the system and simulated experiments. The results showed that the unit can be run without human intervention to full load, where water flow, main steam temperature, main steam pressure are within the control range and the operating characteristics are stable, except the manual confirmation,which improves the level of automation.