The first area of this proposed research addresses the fundamentals of silica fouling. It includes research on the chemical kinetics of silica fouling, the measurement of transient local and overall fouling thermal resistance on a heat exchanger surface and the analytical modeling of the solubility and silica fouling of brines containing multi-component dissolved salts. The other major subject of research pertains to silica fouling prevention by magnetic means. Magnetic effects on silica fouling will be investigated by an array of alternative means. They include optical transmission, solubility, polymerization, silica scale formation on heat exchanger surface and direct measurement of in-situ residual magnetization in brines, all aiming to reveal basic mechanism and effectiveness of magnetic anti- scale devices. Silica is an abundant material in nature and exists in large amounts in underground geothermal reservoirs. When the underground water is utilized, as in geothermal power systems, the dissolved silica will precipitate out and deposit on heat exchanger surfaces, forming a thermal insulating fouling layer and reducing the overall heat exchanger efficiency with severe economical and technical consequences. The present research aims to study under what conditions silica fouling will occur and why it does occur. The other objective is to investigate the effectiveness of silica fouling prevention by anti-scale magnetic field devices. The success of the proposed research will greatly improve the efficiency of heat exchangers involving underground water and will expedite a greater utilization worldwide of geothermal energy for power generation.
