poistohöyryn

Poistohöyryn, often translated as exhaust steam, refers to the steam that has been used to perform work, typically in a steam engine or turbine, and is then released from the system. This steam has expanded and cooled, having transferred a significant portion of its thermal energy to mechanical energy. In many industrial applications, particularly in power generation, exhaust steam from a high-pressure turbine may be further utilized in a lower-pressure turbine to extract more energy before being condensed. This process of reusing exhaust steam is known as regeneration and improves the overall efficiency of the steam cycle.

The temperature and pressure of exhaust steam are considerably lower than that of the steam entering the engine or turbine. Its state is often a mixture of water droplets and vapor. In closed-loop steam systems, the exhaust steam is typically directed to a condenser, where it is cooled and converted back into liquid water. This condensate is then pumped back to the boiler to be reheated and turned into steam again, completing the cycle. In some open systems, such as in older locomotive engines, exhaust steam was simply released into the atmosphere. The effective management and utilization of exhaust steam are crucial for optimizing energy efficiency in steam-powered processes.