Particulate fouling is a common fouling in heat exchange equipment, it causes tube corrosion and increases flow resistance. Particulate fouling increases the hidden danger of equipment and requires high treatment costs. In this paper, a novel Ni−P−TiO₂ composite coating is prepared on 316 stainless steel using electroless plating and the fouling inhibition characteristics of the novel composite coating are studied using a dynamic monitoring experimental system. The experimental results show that the fouling thermal resistance of the Ni−P−TiO₂ composite coating is obviously lower than that of 316 stainless steel under the same working conditions. With the increase in cooling water velocity and inlet temperature, the surface fouling thermal resistance decreases, while, with the increase in particle concentration, the fouling thermal resistance increases. Based on DLVO theory, it is found that the surface energy of Ni−P−TiO₂ composite coating is close to the best surface energy for inhibiting particulate fouling deposition, which can significantly inhibit particulate fouling deposition. Compared with the stainless-steel surface of a conventional plate heat exchanger, the Ni−P−TiO₂ composite coating not only inhibits the accumulation of particulate fouling, but also reduces the adhesion strength of particulate fouling; additionally, the fouling is easier to strip off the heat exchange surface, which realizes the lasting and efficient fouling inhibition on the heat exchange surface. The research results can provide a data reference for the fouling inhibition design and daily efficient operation of heat exchangers.

This paper mainly discusses the relevance of some cooling-water quality parameters and the cooling-water fouling mechanism. By using plate and shell-and-tube heat exchanger experimental systems that are built to simulate the practical operation of heat exchangers, we acquired groups of data of water quality parameters such as Fe³⁺ and Cl⁻ in the cycle process. Then some interaction analyses were made to study the connection between water quality parameters and fouling deposition, and the results indicate that water quality parameters influence each other in a cycle process and the interconnections of water quality parameters have a direct and obvious impact on cooling-water fouling growth in the early operation stage. Later, fouling growth becomes stable for the reason that each parameter achieves a dynamic balance. Cooling-water fouling growth is a comprehensive result of water quality parameter dynamic changes.