炉龄

zhè kě yǐ yán cháng lú líng

这可以延长炉龄。

It can lengthen the life of a furnace.

jīng jì lú líng de què qiè dìng yì shí jì shang shì bù cún zài de

经济炉龄的确切定义实际上是不存在的。

The definition of economic furnace life is not in existence.