Improving self-cleaning system for de-fouling thermal power plant heat exchangers: Case study

Fouling of heat transfer tubes was major threat on the heat transfer efficiency of the condenser at the case study thermal power plant. Such that the mechanical methods used to clean the tubes were inefficient in dealing with the increasing precipitation of insoluble metal salts on the tube walls, which in turn impeded the heat transfer process. A the system of injecting spherical rubber balls into the cooling water along its flow along the tube to scrub dirty on the tube surfaces as well as to create turbulence which disturbs the settling of the dirty on the tube walls was investigated using Finite Element Analysis. Ball sizes of diameter less than tube size were considered favorable so as to carter for possible thermal linear expansion of the rubber material on exposure to temperature. A magnetic water treatment unit was also added to enable the formation of weak precipitates of the metal salts, which has reduced tendency to stick onto the tube walls. This system was found to achieve substantial savings in terms of reducing downtime on condenser cleaning at the thermal power plant.