For the system of ultra low pressure economizer and their derivative system

there are four major problems

including heating surface abrasion

ash deposition and blocking

tube leakage and heating surface corrosion. Taking the optimization reform of ultra low pressure economizer of a 300 MW unit as an example

the improvement measures of the optimization reform were proposed from the aspects of structure and system. In the design of ultra low pressure economizer system

some methods were adopted

such as increasing the design flow rate of the flue gas reasonably

choosing the location of the heating surface reasonably

setting up front ash removal device and online ash conveying device

and optimizing the SCR ammonia injection system. In the structural design of the heating surface

some methods such as adjusting the structural parameters of the heating surface

adopting single and small fin structure and sealing the tube sheet and the shell with a sealing ring were adopted. Considering the difference in coal quality and operation between the different units

the design principles were proposed. These research results can provide references for the optimization reform of ultra low pressure economizer.