柴油机用的冷却水应是清洁的软水。一般说来,经过沉淀的雨水、雪水和以它们为水源的自来水属于软水。软水生成水垢少并质软易清除。井水、泉水、河水以及以它们为水源的自来水属于硬水。硬水中含碳酸氢钙和碳酸氢镁等杂物,受 The cooling water for diesel engine should be clean soft water. In general, precipitated rain, snow water and tap water from them are soft water. Soft water generated less scale and soft and easy to remove. Well water, spring water, river water and tap water from them are hard water. Hard water containing calcium bicarbonate and magnesium bicarbonate and other debris, by