6 – 80 A geothermal power plant uses geothermal water extracted at 160◦C at a rate of 440 kg/s as the heat source and produces 22 MW of net power. If the environment temperature is 25◦C, determine (a) the actual thermal efficiency, (b) the maximum possible thermal efficiency, and (c) the actual rate of heat rejection from this power plant.
A geothermal power plant uses geothermal liquid water at 160◦ at a specified rate as the heat source. The actual and maximum possible thermal efficiencies and the rate of heat reject from this power plant are to be determined.
Assumption 1 The power plant operates steadily. 2 The kinetic and potential energy changes are zero. 3 Steam properties are used for geothermal water.
Properties Using saturated liquid properties, the source and the sink state enthalpies of geothermal water are (Table A-4)