冬季使用内燃机须以防冻液作为冷却液。目前,一般都采用乙二醇作为防冻剂。无论乙二醇还是水,对金属都有一定的腐蚀性,需要在防冻液中加入防腐剂。有的防冻液在出厂时防冻和防腐指标就不合格,有的防冻液随着使用时间的延长,乙二醇会逐渐被氧化衰变,防腐剂不断被消耗掉;当防冻液质量下降到一定程度后,冷却系统就会出现腐蚀或达不到防冻要求。因此,为了保证防冻液的质量,使用前和使用中都 Winter use of internal combustion engines to antifreeze as a coolant. At present, ethylene glycol is generally used as antifreeze. Either glycol or water, the metal has a certain corrosive, need to add preservatives in antifreeze. Some antifreeze at the factory defrosting and anti-corrosion indicators on the unqualified, and some antifreeze with the use of time, ethylene glycol will gradually oxidative decay, preservatives continue to be consumed; when the antifreeze quality down to a certain extent After the cooling system will appear corrosion or antifreeze requirements. Therefore, in order to ensure the quality of antifreeze, both before and during use