In tower-type solar thermal power plants, the performance of the steam turbine unit plays a critical role in determining the plant’s power generation efficiency. This necessitates that the steam turbine unit achieve the highest possible cycle thermal efficiency, thereby reducing the plant’s electricity generation costs. Currently, tower-type solar thermal power plants... Power generation steam turbine unit With capacities ranging from 10 to 150 megawatts and parameter ranges from 12 to 16.5 MPa to 520 to 585°C, the capacity and parameters of steam turbine units in tower-type solar thermal power plants are generally lower than those of existing subcritical coal-fired power units and significantly lower than those of supercritical and ultra-supercritical coal-fired power units. Consequently, the cycle thermal efficiency of steam turbine units in tower-type solar thermal power plants is not high. To address this issue, it is necessary both to optimize the operating parameters and to upgrade the existing turbine units, thereby enhancing the overall power plant’s generation efficiency. Currently, there are numerous methods available for improving the cycle thermal efficiency of turbine units, including reheating and supplementary combustion—energy-saving and consumption-reducing measures that can markedly boost turbine efficiency. However, further improvements in unit efficiency still face technical bottlenecks. In light of this situation, technical experts in this field are dedicated to developing a new type of power-generation turbine unit specifically designed for tower-type solar thermal power systems, one that can once again raise the efficiency of these units beyond current levels.

　　In light of the aforementioned shortcomings of existing technologies, technicians have developed a steam turbine generator set based on a tower-type solar thermal power plant. To address the technical issues mentioned above, this... Power generation steam turbine unit The following technical solution is adopted: a power-generation steam turbine unit comprising a solar thermal exchange unit, a steam Brayton cycle, and a steam Rankine cycle. The solar thermal exchange unit includes a first superheater, a first reheater, a second superheater, and a second reheater. The steam Brayton cycle comprises a compressor, a regenerator, a high-pressure turbine, an intermediate heat exchanger, and a first generator. The outlet of the compressor is connected to the low-temperature side inlet of the regenerator; the high-temperature side outlet of the regenerator is connected to the high-temperature side inlet of the intermediate heat exchanger; and the high-temperature side inlet of the intermediate heat exchanger is connected to the inlet of the compressor. The steam Rankine cycle comprises a condensate pump, a low-pressure heater, an oxygen remover, a feedwater pump, a high-pressure heater, a medium-pressure turbine, a low-pressure turbine, a condenser, and a second generator. The outlet of the high-pressure heater is connected to the low-temperature side inlet of the intermediate heat exchanger; the low-temperature side inlet of the intermediate heat exchanger is connected to the inlet of the first superheater; the inlet of the high-pressure turbine is connected to the inlet of the first reheater; the outlet of the medium-pressure turbine is connected to the inlet of the second reheater; and the second reheater is connected to the inlet of the condenser. The high-pressure turbine, the compressor, and the first generator are arranged coaxially. The medium-pressure turbine, the low-pressure turbine, and the second generator are also arranged coaxially. The steam turbine unit of the power plant further includes a heat collection system, which is connected to the solar thermal exchange unit and provides heat for both the steam Brayton cycle and the steam Rankine cycle. The heat collection system is a condensation-based heat collection system. The steam turbine unit of the power plant also includes a first extraction steam pipe connecting the medium-pressure turbine to the high-pressure heater. The power-generation steam turbine unit further includes a second extraction steam pipe connecting the low-pressure turbine to the low-pressure heater, as well as a third extraction steam pipe connecting the low-pressure turbine to the oxygen remover.

　　Compared to existing technologies, the aforementioned new type... Power generation steam turbine unit It offers the following beneficial effects: Without raising the unit’s temperature parameters, by organically integrating the Brayton cycle and the Rankine cycle, on the one hand, the thermal efficiency of the Rankine cycle can be significantly improved; on the other hand, thanks to the large mass flow rate of the working fluid through the high-pressure turbine, the internal efficiency of the high-pressure turbine is enhanced, thereby ensuring the thermal efficiency of the Brayton cycle. Ultimately, this leads to a significant improvement in the overall thermal efficiency of the entire unit.