Research and Application of Corrosion and Scaling Prevention Strategies for Long-Distance Heating Pipe Network with Large Temperature Difference

Abstract

Ningxia A Heat Supply Company adopted the large temperature difference long-distance heating technology.During two consecutive heating seasons from 2019 to 2021， significant scaling， pitting corrosion of stainless steel and corrosion of carbon steel were observed in the secondary pipeline network， which severely impacted the heating effect for residents during the winter.The heat supply company conducted research and development on scale and corrosion inhibitors，as well as studies on the critical conditions for pitting corrosion，based on the characteristics of its water quality and operating conditions.Ultimately， an anti-corrosion and anti-scaling strategy centered on the addition of TC-type scale and corrosion inhibitors was determined.Through industrial trials， random inspections of the heat exchanger plates revealed no significant pitting or scaling， and the results of carbon steel corrosion coupon tests indicated that the corrosion rate of the inner pipeline walls was effectively controlled.This ensured the safe and economical operation of the heating system.The corrosion and scale prevention strategy has shown great potential for broader application in the same type of heating systems.

Keywords

• heat supply network； anti-corrosion and anti-scaling strategy； pitting corrosion of stainless steel； corrosion of carbon steel； large temperature difference