the plant cycle is 100% thermal efficient, what will be the turbine power output

ID: 1857499 • Letter: T

Question

the plant cycle is 100% thermal

efficient, what will be the turbine power output?

4. A refrigerator is situated in an insulated room; it has a 2-hp motor that drives a

compressor. Over a 30 minute period of time the refrigerator dumps 8000 kJ of heating

from the coils on its back to the room. Calculate the increase in internal energy in the

system if the system is the room without the refrigerator. Calculate the increase in

internal energy in the system if the system is the room with the refrigerator. How much

heat is carried away from the space containing the food inside the refrigerator if the

internal energy of the refrigerator (the solid structure) is unchanged during the process?

1) turbine net power output would be equal to total heat input

since 100% efficient thermal power plant is only an idealised case, it is therefore a carnot cycle and we have

efficiency = W/Qin

1 = W/Q

W = Q

4) heat dumping rate = 8000*1000/30*60 = 40000/9 Watt

power of compressor = 2hp = 1491.4 watt

a) increase in internal energy in the system if the system is the room without the refrigerator

Q = U + W

change in internal energy = Q = 40000/9

b)increase in internal energy in the system if the system is the room with the refrigerator

= zero (since refrigerator works on a closed cyclic process and no heat or work is added to the system)

c) since refrigerator works on a closed cyclic process; change in internal energy must be zero

Therefore, heat carried away from space = 40000/9 - 1491.4 = 2953.04 Watt

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.