| The slot-helix finned tube is a new type of high efficiency finned tube which is further improved on the original continuous helical finned tube.Compared with the traditional continuous spiral finned tube,the lot-helix finned tube has many advantages,of simple manufacture,larger overall surface area per unit length,better heat transfer performance,less ash accumulation,etc.,which has been successfully applied in the heat recovery boiler and other Large-scale flue gas recovery devices.However,there are few kinds of fundamental researches on the heat transfer enhancement of the slothelix finned tube,which limits the application and optimization of such finned tube heat exchanger in practical engineering.In this article,numerical simulation is applied to study and analyze a variety of structures and design schemes that affect the heat transfer characteristics,resistance characteristics and comprehensive characteristics.In this paper,Fluent software is used to analyze the effects of variations in geometric parameters such as fin height,fin spacing,sawtooth height,serration width and transverse tube spacing on the performance of heat exchangers.In order to study the impact of these factors,this article has done the following work:(1)The article summarize the progress of research on finned tube heat exchanger at the present stage,introduce the calculation method of spiral finned tube fin efficiency,explain the basic principle of heat transfer enhancement of slot-helix finned tube bundle and the factors which influence its replacement Thermal performance.(2)Using the SolidWorks to establish a simplified slot-helix finned tube bundle model,divide the grid and analyze the grid independence,Through the comparison of the simulation results with the experimental results to verify the feasibility of the model.(3)The parameters in the above model are changed and analyzed separately to obtain the curves of Nu,Eu and j/f factors changes with Re.By comparing these curves,the influence of different structural parameters on the performance of the heat exchanger under the same Re value is obtained and analyzed,which provides a reference for the selection,design and optimization of slot-helix finned tube.After analysis,it is known that within the scope of this study,the changes of various structural parameters have a weak effect on Nu;the variation of sawtooth width has a subtle effect on the performance of slot-helix finned tube bundle;The Eu value increases significantly with the increasing fin height or sawtooth height and decreases significantly as the fin spacing increases;the j/f factor decreases significantly with the increase of the fin height or sawtooth height;there is a combination of horizontal and longitudinal tube spacing to optimize the performance of the helical finned tube heat exchanger. |
