saturated water vapor, i.e., steam is commonly used as heat source in heat-exchanger applications. why saturated vapor? why saturated water vapor? in plant for any reasonable size, several varieties of saturated steam are commonly available, for example, saturated steam at 4,5,9,17 and 33 bar. but the higher the pressure the lower the useful energy content (why?) and the greater the unit cost. why then is higher-pressure steam used?
A boiler necessarily provides saturated steam (water vapor) at its given operating pressure. To add more energy to the steam (superheated steam) a separate heat exchanger at a higher operating temperature must be added increasing system complexity without necessarily increasing efficiency for heating steam. Superheated steam may be used in marine turbines to increase power while reducing condensation within the initial turbine blade stages (also reducing the required size of the initial turbine stages). For heating purposes saturated steam gives up its heat energy as it condenses and superheated steam may be too hot for a given heating application while merely delaying condensation within a heat exchanger.
You need to provide details of the complete cycle of usage of this steam. Otherwise, I cannot answer any of your whys.
