Steam-generator operating system - returns exhaust to two regenerative air-preheaters in series, second being corrosion-resistant

摘要

The method operates a steam-generator with exhaust-heated air-preheating system. It burns pulverised coal with low nitrous oxide content, particularly previously-dried brown coal. Part of the exhaust is tapped off and returned to the fire. The exhaust from the steam-generator(22) is delivered to the air pre-heating system(1), which comprises two regenerative heaters (2,3). In the first it is cooled, part being then fed to the second, whose exhaust side is corrosion-resistant, being further cooled and discharged. The rest of the exhaust is delivered to the fire(12). ADVANTAGE - Reduces exhaust temperature with consequent improved efficiency.