Answer to Question #94431 in Molecular Physics | Thermodynamics for Amit Rajaram Shinde

Question

By burning a fuel the rate of heat release is 500 kw at 2000 K. Then energy is absorbed in a metallurgical furnace at the rate of 480 KW at 1000 K. If surrounding temperature is 300 K,the second law efficiency will be equal to?
a) 96 %
b) 84 %
c) 79 %
d) 64 %

Answer 1

The second law efficiency, or exergy efficiency is calculated as:

$$\eta_B=\frac{B_{out}}{B_{in}}$$

In our case, this implies:

$$\eta_B=\frac{480kW}{500kW}=0.96=96 \%$$

Answer:a) 96%