A preliminary design of an axial turbine with a capacity of 400 MW for Allam cycle at an initial pressure of 30 MPa and an initial temperature of 1150 °C with a back pressure of 3 MPa is considered. The use of carbon dioxide as a working substance made it possible to create a small-sized powerful turbine, which has high efficiency both at the nominal and part-load operation conditions.
To achieve such results, a novel nozzle governing scheme was used for the turbine, new control valves with zero steam leakage along the stems were developed, novel bandages were used for the blade row allowing to reduce substantially the endwall losses. The aerodynamic calculations of the turbine flow path revealed the possibility to obtain a turbine polytropic efficiency of 88.2%. Taking into account the relatively smaller blade lengths, it is a sufficiently high-performance indicator.
The report also presents the thermal scheme of Allam cycle and the analyzes of its practical implementation problems.
