Chapter 7, Problem 7.8P

The power of a steam turbine in a thermal power plant is 60 MW. Water vapor enters the turbine at 3MPa pressure, 4000C temperature and 50 m / s speed, 10 kPa pressure, 0.9 dry degree and 200 m / s speed leaves the turbine. Considering the turbine as adiabatic; 1-Find the mass flow of steam 2-Find the turbine outlet cross-sectional area, its ratio (A2 / A1) to the inlet cross-sectional area.

one kg of air is compressed in a cylinder according to the law PV^1.3= constant. If intital temperature is 100°C amd compression ratio is 15, find the work done and change in entropy of air.

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A condenser (heat exchanger) brings 1 kg/s water flow at 10 kPa quality 95% to saturated liquid at 10 kPa. The cooling is done by lake water at 20 degree Celsius that returns to the lake at 30 degree Celsius. For an insulated condenser, find the flow rate of cooling water.

18. Saturated water at 200 psia is heated at constant pressure in a reversible non-flow process until it becomes saturated vapor. Find its change in entropy in BTU/lb-R

3. An adiabatic compressor takes argon from 100 kPa, 300 K to 2000 kPa. The compressor efficiency is 80%. (a) Find the outlet temperature (K) and the work (kJ/kg) (b) Find the entropy generation (kJ/kg-K)

Steam to a turbine at a mass flow rate of 1.4 kg/s, 700 kPa pressure and 400 °C enters the temperature. Steam at 100 kPa pressure and 1.4 m3/kg specific volume exits the turbine. Heat transfer from turbine to environment 50 kW, with turbine Since the boundary temperature between the environment is 70 °C, a) Find the power produced by the turbine, entropy produced in the turbine and isentropic efficiency of the turbine. Note: The changes in kinetic and potential energies will be neglected and T (K) = 273 + °C will be taken.

A turbine, operating under steady- flow conditions, reccives 1000 kg/min of stcam. At the inlet, the pressure is 30 bar, the temperature is 400°C, the velocity At the exit, the pressure is 0.7 bar, the quality is (100%), and the velocity is 100 m/s. If the turbine produced a power output of 9300 KW. By using the energy balance of open system with sutable tables, answer the following: (a) What are the main assumptions ? (b) Calculate dh, AKe ? (c) Calculate the rate of heat transfer between the turbine and surroundings, in kW.

A nozzle is a device for measuring the velocity of flow. At inlet to a nozzle the enthalpy is 3026 kJ/k, the velocity is 60 m/s. At exit from the nozzle the enthalpy is 2790 kJ/kg. The nozzle is horizontal and there is a negligible heat loss from the nozzle. Find he velocity at nozzle exit The inlet area is 0.1 m2 and the specific volume at the inlet is 0.19 m²/s, find the mass flow rate • f the specific volume at the nozzle exit is 0.5 m²/kg, find the exit area of the nozzle (688m/s) (0.36kg/s) (0.0299m2) Air and fuel enter a furnace used for home heating. The air has an enthalpy of 320 kJ/kg and the fuel has an enthalpy of 43027 kJ/kg. The gases leaving the furnace has an enthalpy of 616 kJ/kg. There are 17 kgair / kgfuel, water circulated through the wall furnace receiving heat. The hose required 17.02 kW of heat, what is the fuel consumption per day. (41 kg/day)