 Ch 6. Entropy Multimedia Engineering Thermodynamics Entropy Tds Relations EntropyChange IsentropicProcess IsentropicEfficiency EntropyBalance (1) EntropyBalance (2) ReversibleWork
 Chapter 1. Basics 2. Pure Substances 3. First Law 4. Energy Analysis 5. Second Law 6. Entropy 7. Exergy Analysis 8. Gas Power Cyc 9. Brayton Cycle 10. Rankine Cycle Appendix Basic Math Units Thermo Tables Search eBooks Dynamics Statics Mechanics Fluids Thermodynamics Math Author(s): Meirong Huang Kurt Gramoll ©Kurt Gramoll THERMODYNAMICS - CASE STUDY Introduction Problem Graphic Power Generated by a Hydraulic Turbine A hydroelectric power plant is to be built in a mountain region. Water flows from the elevated reservoir through pipes to a hydraulic turbine, whose shaft is connected to a electric generator. Thus, the mechanical energy of water is converted to electrical energy. A designer orders some 0.5-m-diameter-pipes but he needs the engineer to specify the exact number of intake pipes. What is known: The water surface in the reservoir is 105 m higher than the turbine. The entrance to the intake pipes is located 5 m below the water surface in the reservoir. Water enters the intake pipe at 1 m/s and exhausts to a river directly after exiting the turbine with almost the same velocity. The ambient pressure is 1 bar. The pipe diameter is 0.5 m. The power output is 1 MW. Question A Hydroelectric Power Plant How many intake pipes are to be installed? Approach Take the system from point 1 to 2 shown on the left as a control volume. Consider the power plant works in reversible and steady flow conditions. Then the power output from the power plant equals the reversible steady-flow work of the turbine. Schematic of the Power Plant