Calculation method of moisture loss in steam turbine

A calculation method of moisture loss in a steam turbine to calculate an amount of moisture loss generated when a steam condition in the steam turbine becomes wet steam, by an arithmetic processing unit, comprising:

• calculating a wetness fraction at the inlet and outlet of each of a stationary blade cascade and a rotor blade cascade;
• classifying the moisture loss into (1) supersaturation loss generated when steam expands to supersaturate at the blade cascade, (2) condensation loss generated when steam around water droplets condenses, (3) acceleration loss generated due to a difference in velocity between water droplets and steam, (4) braking loss generated when water droplets collide against the suction sides of rotor blades, (5) capture loss generated when water droplets collide against the surfaces of the stationary and rotor blades, and (6) pumping loss generated when water droplets adhere to the surfaces of the rotor blades, and selecting a loss used for calculation of the moisture loss amount from the individual losses (1) to (6) on the basis of the wetness fraction of steam at the inlet and outlet of the each blade cascade;
• calculating an amount of the each selected loss;
• and
• calculating a moisture loss amount at each blade cascade on the basis of the each calculated loss amount.