7 . Please show technical characteristics of steam turbine propulsion plant?

-Working substance is high-pressure steam generated in main boiler

-Output is continuous: it is the most important advantage of turbines.

-Working substance flows continuously through the turbine so rotating moment, heat and mechanical load in the parts of engine are stable. Therefore, turbine has a high longevity.

-All moving parts of turbine are installed on a rotor, rotated with the same certain direction and speed. It permits to reduce mechanical losses, raise efficiency of turbine. When working, turbine doesn't generate inertia forces.

-Output of turbine depends on only parameters and amount of steam that flow through turbine. So turbine can generate a large power.

-Turbine direction is determined by direction of steam, which acts on blades wheel of turbine. With a certain blade wheel, turbine cannot reverse its self.

-Turbine's revolution is much higher than optimum range of propeller's revolution, so turbine cannot directly drive propeller

-Gas temperature in boiler combustion chamber is limited by heat durability of material. Cycle temperature is low; boiler and transmission pipes have heat losses so efficiency of propulsion plant is low.

-Efficiency of the steam turbine propulsion plant is about 22 ¸ 26%

-High pressure and temperature steam flows continuously inside transmission pipes. It may cause danger to operators when emergency happens.

-It requires having a high quality of water in the system.

-It takes a long time to prepare for starting the system, so it is not flexible.