Supercritical steam generating units operate at pressures above which value in MPa?

Supercritical steam generating units operate at pressures above 22 MPa. In a supercritical steam generator, the water is heated to a point where it becomes a supercritical fluid, meaning it is above the critical temperature and critical pressure. The critical pressure for water is approximately 22.1 MPa (or roughly 3200 psi). At this pressure, there is no distinction between liquid and vapor phases, allowing for more efficient energy production and higher efficiency rates compared to subcritical systems.

Operating at supercritical conditions allows for higher temperatures and pressures, which results in a higher thermal efficiency. This is why the industry has moved towards supercritical technology for modern steam power plants; it helps in reducing fuel consumption and emissions.

Understanding that the supercritical threshold is set just above 22 MPa can help clarify the operational limits and benefits associated with supercritical steam generating units, as well as their environmental advantages.