Selecting the Startup Option for the Surgut GRES-2 800-MW Power Unit in the Absence of Its Own Steam Source

Matters concerned with the tenacity of thermal power plants still remain of issue for the power industry of Russia. In view of power capacities concentrated within the boundaries of a single power plant, various off-design situations (accidents) occur in it, and the likelihood of such situations to occur increases significantly since the tendency toward aging of the existing equipment is still continuing. The situation in which the Surgut GRES-2 thermal power plant’s generating steam power equipment become shut down completely (so-called blackout) considered in the article is one of such contingencies. To cope with system accidents of this sort, relevant possibilities and means must be available. The Surgut GRES-2 power plant consists of two sages: six 800-MW seam power units (SPUs) and two 400-MW combined cycle units (CCUs). The article presents solutions to the problem stated above through interaction of the equipment of the power plant’s two stages. Five possible schemes for starting the SPUs from zero when there is loss of auxiliary steam are considered. The organizational and technical measures necessary for implementing these options are developed. The minimal requirements for an external steam source (flowrate, pressure, and temperature) are determined theoretically and confirmed by tests. Calculations of the CCU’s heat-recovery steam generator (HRSG) are carried out, which confirmed its ability to behave as the external steam source. For two promising options, schemes for the necessary modification of the power units are developed, and an aggregative comparative assessment of the costs for implementing them is carried out.