Losses in Steam Turbines

Losses in steam turbines can be mainly classified into two types. They are:

Internal losses (which occur within the flow of steam) and
External losses (which occur outside the turbine casing).

Internal Losses in Steam Turbines:

The internal losses in steam turbines may be enumerated as follows:

1. Losses in regulating valves:

2. Nozzle friction losses:

3. Blade friction losses:

4. Disc friction losses:

5. Partial admission losses:

6. Gland leakage losses:

7. Residual velocity loss:

8. Carry-over losses:

External losses in steam turbines:

There are some energy losses in the bearings and governing mechanisms which can be reduced by improving the lubrication system.
Some energy is consumed by oil pumps. Since the turbines are adequately insulated the surface heat loss by convection and radiation is small.

Reference: Power Plant Engineering by PK Nag – Page 487

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