Chapter 8, Problem 8.23P

In the Rankine cycle for a steam power plant the turbine entry and exit enthalpies are 2803 kJ/kg and 1800 kJ/kg, respectively. The enthalpies of water at pump entry and exit are 121 kJ/kg and 124 kJ/kg, respectively. The specific steam consumption (in kg/kW.h) of the cycle is_

A 20 mw steam power plant working on a rankine cycle operates between pressures of 80 bar and 0.1 bar. The maximum cycle temperature is 600 °c if the steam turbine efficiency is 90% calculate thermal efficiency of the cycle and mass flow rate of the steam.

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efficiency, and (c) the combined engine efficiency. (3) Steam at 5.2 MPa, 400°C expands in a Rankine turbine to 0.036MP.. For 136 kg/s of steam, determine the work, the thermal efficiency, and the steam rate (a) fot the cycle(b) for the turbine, (c) for an actual turbine with the same specifications, the brake steam rate is 4.80 kg/kwh ang the driven electric generator has an efficiency of 93%, Find brake thermal efficiency, brake engine efficiency, combined work, and quality or temperature of exhaust steam. (4) A turbine receives steam at 10 MPa, 600°C and exhaust it at 0.2 MPa, (a) for the ideal Rankine engine

= 10000 kg/h. Also, the plant has Q2. There are many electrical power plants in Iraq. The rate of steam flow : the following data refer to a simple steam power plant : Calculate : (i) Power output of the turbine. (ii) Heat transfer per hour in the boiler and condenser separately. 65 bar 70 bar 400°C Boiler 1 60 bar, 380°C 4 Wout Pump Turbine G Electricity 2 0.1 bar, 0.9 dry 3 Condenser 0.09 bar Saturated liquid

7. Steam at 7.2 MPa, 600OC expands in a Rankine turbine to 0.45 MPa. For 180 kg/s of steam, determine the work, the thermal efficiency, and the steam rate (a) for the cycle, (b) for the turbine with the same specifications, the brake steam is 7.40 kg/kW-h and the driven electric generator has an efficiency of 91%. (c) Find eb, nb, WK, and quality or actual exhaust steam. Please answer letter c. Thanks

3. A medium size power station is used to produce 30 MW net power for a refinery. The station uses steam as the operating fluid and operates according to the Carnot cycle between the pressure limits of 0.4 bar and 35 bar. Steam enters the boiler as a saturated liquid and leaves it as a dry saturated vapour. (vii) Using the highest and lowest temperature values in the cycle, recalculate the efficiency of the cycle and show that it is equivalent to the result in part (vi). (viii) Calculate the thermal efficiency of the power station if the isentropic efficiency of the steam turbine is 94%. (ix) State main disadvantages of using the Carnot cycle as the basis for a power station. (x) State the name of the cycle that is used in practice in power stations, along with three key benefits over the Carnot cycle.

Find the Rankine cycle thermal efficiency of a steam plant with the following enthalpies in KJ/kg: entering turbine: 3100, leaving turbine= 2400, entering pump= 140 leaving pump= 180.

In a Rankine cycle, the steam inlet to turbine is saturated at a pressure of 35 bar and the exhaust pressure is 0.2 bar. Determine, (1) The pump work (2) The turbine work. Assume mass flow rate of 9.5 kg/s.