What is the main function of moisture separator reheaters (MSRs) in a steam turbine cycle?

The main functions of moisture separator reheaters (MSRs) in a steam turbine cycle are to remove moisture from the steam after it has passed through the high-pressure turbine stage and to superheat the steam before it enters the low-pressure turbine stages. Steam exiting the high-pressure turbine contains a significant amount of moisture due to expansion and cooling. This moisture can cause erosion and damage to the low-pressure turbine blades, reducing their efficiency and lifespan. The moisture separator removes this liquid water, typically using a series of baffles or vanes to cause the water droplets to separate from the steam. The reheater then uses steam from the reactor or another high-temperature source to superheat the steam. Superheating increases the steam's temperature and energy content, improving the overall efficiency of the turbine cycle. This higher-energy steam entering the low-pressure turbines results in a greater power output. By removing moisture and superheating the steam, MSRs also improve the thermodynamic efficiency of the cycle. This means that more of the thermal energy from the reactor is converted into electrical energy. MSRs typically consist of a series of heat exchangers. Steam from the high-pressure turbine passes through the shell side of the heat exchanger, while high-pressure steam from the reactor or another source passes through the tube side, providing the heat for superheating. The condensate from the reheater steam is typically returned to the feedwater system to recover the heat and conserve water. In summary, MSRs protect turbine blades, increase turbine efficiency, and improve overall power plant performance by removing moisture and superheating steam between turbine stages.