A steam engine intakes 80 g steam at 100^° C per minute and cools it down to 30^° C. The heat energy consumed by the steam engine per minute is \ \ \…

A steam engine intakes $\displaystyle 80 g$ steam at $\displaystyle 100^{\circ} \mathrm{C}$ per minute and cools it down to $\displaystyle 30^{\circ} \mathrm{C}$. The heat energy consumed by the steam engine per minute is \_\_\_\_ Cal. (Latent heat of vaporization of steam $\displaystyle =540 \mathrm{Cal} / \mathrm{g}$ )