Ageothermal plant uses geothermal water (yes a liquid) extracted from beneath the earth using drilling apparatus. the geothermal water (a condensed liquid) comes up at a temperature of 200 c at a rate of 200 kg/s. it is used to drive a turbine that extracts 6000 kw of power. the water leaves the turbine at 80 c and enters a lake at 25 c. what is the actual thermal efficiency of the turbine in percent to three significant digits (do not enter a percent )

To solve this problem it is necessary to apply the concepts of heat change and thermal efficiency.

The heat rate can be expressed under the function

Where,

m = Mass

Enthalpy at each state

Our values are given as,

From the tables of Enthalpy of Water at 200°C (Saturated liquid state)

At the same time for 80°C

Applying the equation of Heat,

Replacing,

Therefore the efficiency would be

Therefore the actual thermal efficiency of the turbine in percent is 0.0579.

i think the answer is a, hope this is right, that would be my best guess.