There are seven internal losses in the steam turbine:
⑴ Nozzle loss. When the steam flows through the nozzle, some of the steam generates disturbance and vortex, and the steam and the surface of the nozzle have friction, which causes a loss of functional power.
⑵ Loss of moving leaves. When steam flows through the moving blades, due to friction and eddy currents between the steam flow and the surface of the moving blades, there will also be a loss of functional power.
(3) Loss of residual speed. When the steam is discharged from the rotor blade, the absolute speed has a certain kinetic energy. If this part of the kinetic energy is not used, it will be converted into heat energy again, which will increase the exhaust enthalpy value and cause a loss of function.
⑷ Steam leakage loss. It includes two parts: one part is the steam leakage at the end of the cylinder shaft seal. The other part is the steam leakage loss within the stage, including the steam leakage loss at the baffle steam seal, rotor blade and cylinder clearance.
⑸ Friction blast loss. Friction loss refers to the loss caused by friction with steam when the impeller rotates, and the power consumed by the steam on both sides of the impeller being rotated to form a steam vortex. Blasting loss refers to the frictional loss caused by steam on both sides of the cascade, and in part of the steam inlet stage, when the rotor blade rotates in the part where no steam flows, the steam is swollen from one side of the blade to the other Additional losses incurred. Friction loss and blast loss are collectively called friction blast loss.
⑹ Steam loss. In the partial steam inlet stage, the steam from the nozzle only passes through the flow path of part of the moving blades, while the other moving blades are filled with stagnant steam. When this part of the rotating blade rotates to align with the nozzle again, the main steam flow from the nozzle should first repel the trapped steam, which reduces the speed of the steam flow. There was an energy loss.
⑺ Moisture loss. The velocity of water droplets in wet steam is smaller than that of steam, and the steam molecules consume a part of the energy to accelerate the water droplets and cause energy loss. At the same time, due to the low velocity of the water droplets, when it enters the moving blade, it just hits the back of the inlet of the moving blade, which has a braking effect on the impeller and consumes a part of useful work.