Question

A second geothermal power plant, based on the design shown in question 4, (See Image Below) also uses propane as its working fluid. The following specific enthalpies are known: h subscript 1 = -61.0 kJ/kg, h subscript 2 = 564.6 kJ/kg, h subscript 3 = 372.39 kJ/kg and h subscript 4= -64.9 kJ/kg. If the mass flux of working fluid is 79 kg/s, then determine the net rate at which shaft work is done by the cycle. Express your answer in megaWatts and include appropriate units.

QUESTION 4 A geothermal power station (shown below) operates on the Rankine cycle using propane as a working fluid. Energy for the cycle is supplied by geothermal water passing through a heat exchanger (from A to B). Heat Exchanger wp-> Pump Turbine AUT Condenser qout geo= 65 kg/s, enters the heat exchanger with a temperature of 86°C and leaves with a temperature of 10 °C. Propane at 24 bar enters A mass flux of geothermal water the heat exchanger as saturated liquid with a temperature of 25°C and leaves with a temperature of 80 °C. The specific heat capacity at constant pressure of the geothermal water Cp.geo = 3.566 kJ/(kg K). Assuming all the heat lost by the geothermal water is transferred to the propane, determine the mass flux of propane through the heat exchanger. Express your answer in kilograms per second and include appropriate units. 42.92kg/sec

Answer 1

bast work from cycle = is [Turbine work - Pomp work] 4x56164.6 – 342-39) - (-61464.47) 2 1487605 kW = 4.876 MW