省煤器再循环管从汽包水容积最低点引出,接到省煤器入口联箱,其用意是在锅炉启、停过程中,当停止向锅炉给水时,靠汽包-再循环管-省煤器-汽包之间的循环回路,向省煤器供水以防止省煤器管过热,如图1所示。现在国内外的大、中型锅炉大部分都装有省煤器再循环管,有关专著也都认为装设省煤器再循环管能够起到防止省煤器管组汽化、过热、损坏的目的。水电部颁发的锅炉运行规程对此也有明确的规定。但多年来的运行实践表明,再循环管非但未能达到预期的作 The economizer recirculation pipe leads from the lowest point of the drum water volume and receives the header of the economizer. The purpose is to close the inlet of the economizer when the boiler feed water is stopped during the process of starting and stopping the boiler, Economizer - drum loop between the circuit, water supply to the economizer to prevent the economizer tube overheating, as shown in Figure 1. At present, most large and medium-sized boilers at home and abroad are equipped with economizer recirculation pipes, and relevant monographs also consider that installing economizer recirculation pipes can prevent vaporization, overheating and damage of economizer tube sets. Ministry of Water Power issued by the boiler operation rules also have a clear requirement. However, many years of operational practice show that the recycling pipe not only failed to achieve the desired result