Evaluation of the cost-effectiveness of solutions to improve the efficiency of atmospheric deaeration in boiler plants

Abstract

The reliable and economical operation of equipment for thermal power plants, heat supply systems and boiler houses has been a relevant problem in the field of thermal power engineering for many years. In many industries, industrial steam is often used, for which steam boilers are used at thermal power plants. The water consumed by the boilers undergoes pre-treatment, which, in addition to its softening, includes thermal deaeration — the removal of aggressive gases that lead to equipment corrosion. Atmospheric deaerators are often used for this purpose. They are easy to use, quite effective, but have a disadvantage — a considerable amount of heat is lost with the removed flash steam. The article is dedicated to evaluating the cost-effectiveness of the technology for additional heating of return system water using deaerator steam and considering a method for improving the efficiency of atmospheric deaeration by partial closure of flash steam output in boiler plants. The paper presents a calculation of the scheme of operation of a deaeration plant, which makes it possible to increase the efficiency and effectiveness of the boiler house of the AB InBev Efes brewery in Ulyanovsk due to additional heating of return system water with atmospheric deaerator flash steam. The article also discusses the scheme of operation of an atmospheric deaerator, in which the flash steam will be discharged into the atmosphere only if it is necessary to remove aggressive gases. Thanks to the developed scheme, when the deaerator operates with a closed flash steam removal pipeline and without being fed with chemically purified water, the consumption of industrial steam is reduced, especially with a significant return of condensate, which increases the efficiency of the entire boiler room as a whole. According to preliminary calculations, assuming the average return of condensate from production per day of about 300 m3, the production steam savings will be 0.8 tons.