Steam enters a turbine operating at steady state with a specific enthalpy of 1407.6 Btu/lb and expands to the turbine exit where the specific enthalpy is 1236.4 Btu/lb. The mass flow rate is 5 lb/s. During this process, heat transfer to the surroundings occurs at a rate of 40 Btu/s. Neglecting kinetic and potential energy effects, the power developed by the turbine is

The power developed by the turbine is 816 BTU per second.

Explanation:

Thermodynamically speaking, a turbine produces work at the expense of fluid energy. By First Law of Thermodynamics, the energy balance of a turbine working at steady state is:

(1)

Where:

- Heat transfer rate, measured in BTU per second.

- Power developed by the turbine, measured in BTU per second.

- Mass flow rate, measured in pounds per second.

, - Specific enthalpies at inlet and outlet, measured in BTU per pound.

If we know that , , and , then the power developed by the turbine is:

The power developed by the turbine is 816 BTU per second.