Uncertain Factor Analysis Of The Natural Circulation Of Hot Water Boiler Hydrodynamic

It has been30years since the reforming and opening up began，during whichthe boiler manufacturing industry in China has made considerable progress. Forthere is no perfect hydrodynamic calculation as a security guarantee, itresulted in accidents of the natural circulation of hot water boiler water cycle inrecent years, and caused great economic losses. So it is very important toguarantee the practical application of the hot water boiler.Largely on the calculative basis of "natural circulation of hot water boilercalculation, this article develops the natural cycle of the hydrodynamiccalculation software and by the use of this software it analyzes the practicalapplication of the natural circulation of hot water boiler characteristics ofhydrodynamic calculation and uncertainties that affect the water cycle reliability.Main content of the paper are as follows:Based on the natural circulation of hot water boiler working theory andthe hydrodynamic characteristics calculation of mass and momentumconservation, it builds the hydrodynamic computational model for different loopsin the boiler. It develops hydrodynamic calculation software according todifferent hydrodynamic model. Hydrodynamic calculation software calculate svarious characteristics of the water cycle loop using an iterative algorithm withthe constraint of each loop pipeline pressure balance equation. It is taken intoaccount that the loop’s parallel-rising pipe will cause some thermal deviation topipe water cycle less reliable due to uneven heating. It makes the circulatingwater speed check software, and check calculation of the thermal deviation in theloop tube.It analyzes the main indicators to be references for the hydrodynamicanalysis on the natural cycle of hot water boiler. Improving the water cyclereliability is achieved by increasing the loop water circulation flow rate，and avariety of measures to improve the natural circulation of hot water boiler watercycle reliability are summarized and analyzed.Based on Hydrodynamic calculation software and its calculation method,it calculates the hydrodynamic characteristics of the practical application of thehot water boiler. It analyzes the relationship between the total circulation rateand the water cycle reliability of the natural cycle hot water boiler. Taking theloop circulating water speed as the main criterion, it studies the different structure of the deviation of loop and heat pipe water cycle reliability by thecirculation rate impact. It analyzes the relationship between boiler circulationratio and other uncertainties such as heat pipe heat intensity, the increasing oftube length, and complex loop after the transformation of the natural cycle of hotwater boiler. In order to achieve the efficient and safe operation of the naturalcirculation of hot water boiler, it advances some problems needing attention inthe transformation process.Based on the results of boiler hydrodynamic characteristics calculation,it analyze the problems such as the affect on the loop flow and the water cyclereliability made by the falling pipe， which is encountered in the practicaltransformation of the natural circulation of hot water boiler，what’s more，it givesthe solutions as well. It presents a detailed study of the impact of the adding tothe entrance of the falling pipe on the reliability of the water cycle，and get therange of the set circular velocity.