As an efficient heat exchange equipment, plate heat exchanger has the characteristics of high heat exchange efficiency, small footprint, light weight, convenient assembly and disassembly, many types of plates, and low fouling coefficient. It is widely used in heating systems. The heat exchanger has become the core component of the central heating indirect heat exchange unit. So what are the reasons for the failure of plate heat exchangers in the heating industry?
(1) In the secondary grid system for heating, the plate heat exchanger generally uses untreated tap water that contains a large amount of Ca2+, Mg2+ and other scale-forming ions. In the actual production process, the method of adding anti-corrosion and scale inhibitors is often used to reduce the hardness of tap water. Due to inadequate equipment and operation management, the addition of anti-corrosion and scale inhibitors cannot meet the requirements. A large amount of Ca2+ and Mg2+ are saturated and precipitated from the water and deposited on the metal surface of the heat exchanger and the pipe network to form scale.
(2) Dissolved oxygen and salt in the water will cause oxygen corrosion and chemical corrosion to the metal material of the heating system. Since the heating system is composed of a variety of metal materials, in the water containing a large amount of electrolyte salts, galvanic couples and corrosion cells are formed between different metals, which will cause electrochemical corrosion of the heating system metals.
(3) After the sediment and various bacteria, algae and microorganisms in the replenishing water enter the circulating water system, the microorganisms grow and multiply due to the appropriate temperature, which produces a large amount of microbial sludge in the system, which is attached to the heat exchanger and mixed with the scale to form biological properties dirt.