Gas from the combustion of fuel, the heating value of which has been substantially spent and which is, therefore, discarded to the flue or stack.
燃料燃烧产生的气体，其热值已大体上耗尽，因此排入烟道或烟囱。
2
Before entering the existing stack the flue gas has to be reheated to protect the stack against condensates. For reheating the gas gas Heater (GGH) is used.
因此在进入烟囱之前，必须被再度加热而使烟囱不结露，因此烟气换热器就被运用了。
3
Flush system with hydrogen until required purity is reached. Vent all waste hydrogen through a flue or flare stack.