Abstract: Based on the equation of state and the thermodynamic properties of ideal Bose gas, we obtain the ex- pression of efficiency of Diesel cycle which work substance is ideal Bose gas. It is shown through the comparison that the efficiency of heat engine is improved when the Diesel cycle works under quantum degeneracy condition. The resuits obtained should provide theoretical basis for the design of Diesel cycle working under quantum degeneracy conditions.

Key words: ideal Bose gas, Diesel cycle, quantum effects, efficiency of heat engine