Hydrodynamic Optimization Research Of Forced Circulation Hot Water Boiler

There are many factors those affect the economics and reliability of forcedcirculation hot water boiler. This paper summarizes and analyzes the influencingfactors of this boiler’s economy and reliability, as well as the totle pressure drop bychanging the water circulating struction. This paper also made a check calculationfor the heating surface which many occur sub-cooled boiling and saturated boilingeasily of the changed structure.The arrangement modes of parallel tubes can affect the flow deviation andthermal deviation of its’ branch pipes, also affect the reliability of the boiler. Thearrangement modes of parallel tubes can be split into two categories, typicalarrangement and atypical arrangement. This paper calculate an analysis the flowdeviation coefficient and thermal deviation coefficient of every branch pipes indifferent arrangement modes. Also summarized the influencing factors of flowdeviation and thermal deviation. Comparative analysis the advanta ges anddisadvantages of different parallel tubes arrangement modes. Simplified methodcannot desccribe the inlet and outlet of the header, because of the inlet and ouletbeget swirl which can make the static pressure changed. This situation often takeplace in atypical arrangement modes of parrallel tubes. This dissertation discussesthe static pressure distribution of distribution-header and collection-header and flowdeviation coeffic ient of branch pipers, when the arrangement modes of parallel tubesare atypical. Reduce the return water temperature can increase the boiler effic iency,but low temperature return water can causes low temperature corrosin in boilerback-end heating surfaces. First the paper analyzes the boiler’s thermal efficiencyand flue gas acid dew point temperature that is designed in the design conditions.Second the paper analyzes the heating surfaces which easiy take place lowtemperature corrosin. Thirdly, the article sums up the factors of acid dew pointtemperature and how to choose fitting temperature to improve boiler’s efficiency. Italso explains the reasions that how to reduce the low teperature corrosin.