Question

In a Brayton cycle, maximum and minimum temperatures are 1300 K and 295 K respectively. If the compressor and turbine efficiencies are 0.88 and 0.92 respectively, the optimum pressure ratio for maximum work output is _____

• A. 9.26

Answer 1

The correct option is A 9.26
${\text{Maximum temp, T}}_{max}=1300K$

${\text{Manimum temp, T}}_{min}=295K$

$\text{Comressor efficiency}{\eta }_c=0.88K$

$\text{Turbine efficiency},{\eta }_{\tau }=0.92$

$\text{Optimum pressure ratio,}{r}_{opt}={\left({\eta }_c{\eta }_{\tau }\frac{T_{max}}{T_{min}}\right)}^{\frac{\gamma }{2(\gamma -1)}}={(0.88\times 0.92\times \frac{1300}{295})}^{\frac{1.4}{2(1.4-1)}}$

= 9.26