The water medium heat pipe gas-gas heater(MGGH) is an important part of ultra-low flue gas emission technology for coal-fired boilers

of which the operating environment is bad and the corrosion mechanism of the heat exchange tube is complex

it is a key problem to solve the low temperature corrosion of heat exchange tube.Analysis on corrosive mechanism of the heat exchange tube shows that the low temperature section of the gas reheater in the MGGH is located on the No.II serious corrosion zone.There are two engineering techniques to control the low temperature corrosion rate and the heat exchanger tube materials of 316 L

DIN1.4529

plastic and enamel can satisfy the requirement.It finds that the enamel heat exchange tube can meet the engineering requirements through the research and comparison.From several aspects such as the corrosion resistance of sulfuric acid

thermal conductivity

mechanical properties of materials

anti erosion abrasion resistance and engineering cost

the enamel heat exchange tube can solve the problem of low temperature corrosion.Enamel heat exchange tube has excellent performance of low temperature corrosion resistance

wear resistance and heat conduction

and the capability of heat transfer is superior to the steel pipe.It has been verified that the enamel heat exchange tube can satisfy the technical requirement

and has important engineering application by engineering practice.