Question

An air standard diesel engine cycle with cut off ratio 1.2 and compression ratio 14:1 has air inlet at STP conditions. If the engine now operates first with hydrogen gas and then chlorine gas instead of air with arrange them in correct order of their efficiency.

• A. ${\eta }_{air}={\eta }_{H2}={\eta }_{cl2}$
• B. ${\eta }_{air}>{\eta }_{cl2}>{\eta }_{H2}$
• C. ${\eta }_{air}<{\eta }_{H2}>{\eta }_{cl2}$
• D. ${\eta }_{air}>{\eta }_{H2}>{\eta }_{cl2}$

Answer 1

The correct option is A ${\eta }_{air}={\eta }_{H2}={\eta }_{cl2}$

${\eta }_{diesel}=1-\frac{1}{{\gamma }^{\gamma -1}}\left(\frac{{\gamma }_c^{\gamma }-1}{{\gamma }_c-1}\right)$

${\eta }_{diesel}=f(\gamma ,r,r_c)$

now ${\gamma }_{air}={\gamma }_{H_2}={\gamma }_{c{l}_2}=1.4$

and $r_{c}andr$ for all cycles are same

${\eta }_{air}={\eta }_{c_2}={\eta }_{H2}$