Marine Boiler Tubes Spotting Impact on Its Operation Parameters: a Case Study

Abstract

Article deals with ship power engineering, namely with ship steam boiler operation parameters and fuel efficiency. Boiler Aalborg MISSION OL tubes surface scale and soot contamination impact on tubes stress state and operation parameters studied in the article. It is shown that scale contamination on the inner surface of the tubes is the cause of their overheating. Wall temperature difference increase from 10 ⁰С to 145 ⁰С leads increase in the equivalent stress up to 10 times. Scale formation on tube wall increases thermal resistance and became a reason of specific heat flow reduce by 12.7%, which leads to a diminution in the steam productivity of the boiler from 25000 to almost 21000 kg/h and exhaust gas temperature growth by almost 250 ⁰С. The case presented in article is successfully reviewed by the authors in the educational process in the academic disciplines “Basics of Ship Power Engineering” and “Ship Boiler Plants”.