The potential for efficiency improvement depends mainly on the fuel type fired, the exit flue-gas temperature, the process fluid temperature, the low-level heat required, and the excess air etc.

冷凝式锅炉的热效率提高潜力主要取决于燃料种类、锅炉本体的排烟温度、工艺流体的温度、所需的低品位热能的数量、过量空气系数等。

Besides, the fuels with ultra-low level of sulfur or free of sulfur are required for hydrogen fuel cell if its hydrogen is produced from the fuels.

另外，在氢源燃料电池系统中，如果氢来源于燃料油，那么必须使用超低硫或无硫燃料油。

Set the fuel level at its low position.

手柄置于低供油位置。