Effectiveness of the joint scheme of steam-power and combined-cycle power units using the example of the Nevinnomyssk State Regional Thermal Power Plant

Abstract

We attempt to solve the problem of displacing high-temperature steam bleeding in a steam turbine plant at the first regenerative heater after intermediate overheating. This can be achieved when the thermal power plant contains heterogeneous equipment, in particular, a steam turbine and combined cycle power units. The authors proposed an energy-efficient scheme for the joint operation of steam turbine unit and steam-turbine part of a combined cycle plant with the displacement of high-temperature steam onto the high-pressure feed heater (HPFH 2) using the dry steam from the medium-pressure drum of the waste boiler in order to increase the upper limit of the power plant’s control range. For this research, Nevinnomyssk TPP was selected as one of the main energy facilities of the Unified Energy System of Southern Russia. We studied the joint operation of the steam turbine unit K-160-130 and the combined cycle plant CCP-410 manufactured by Siemens, Germany. We developed the methodology and calculated the energy efficiency of the new power plant operation scheme. According to the calculation results, the total increase in power amounted to 6.03 MW, while there was an increase in electrical gross efficiency by 0.64%. An assessment of the economic effect of the applied solution for the conditions of the Nevinnomyssk TPP demonstrated that the annual increase in net profit will amount to 14.47 million rubles, and the payback period of investments is 4.2 months.