Study On The Performance Of Shell And Tube Heat Exchanger With Staggered Louver Baffle

Heat exchangers are equipment widely used in Resources&Power,petrochemical engineering and HVAC(Heating Ventilation Air Conditioning)industries.It is of great significance to improve the heat exchange efficiency of heat exchangers and reduce pump power consumption in energy conservation and pollution reduction.The design and development of high-efficiency heat exchange equipment is particularly important,which is an important measure in energy conservation and emission reduction,especially in the context of "carbon neutrality" and "peak carbon dioxide emissions".The traditional heat exchanger with segmental baffle with simple structure,strong pressure resistance and easy processing and manufacturing is the most widely used type of heat exchange equipment in energy-intensive industries.However,the traditional heat exchanger with segmental baffle has the problems of large pressure drop on the shell side and large flow dead zone behind the baffle because the baffle is arranged perpendicular to the heat exchange tube bundle on the shell side.Based on the above problems,this paper proposes a shell-and-tube heat exchanger with staggered louver baffles aiming to improve the shell-side flow structure of the shell-and-tube heat exchanger,to reduce the consumption of pump power and improve its overall performances.This article provides the design model of the shell-and-tube heat exchanger with staggered louvered baffles,establishes a three-dimensional mathematical model of the shell-and-tube heat exchanger with staggered louvered baffles and generates a complex computational grid.The distribution of velocity field and temperature field can be obtained and the drag reduction mechanism and characteristic can be analyzed through three-dimensional numerical simulation.This article also study differences of heat transfer,resistance and overall performance in different louver baffle inclination angle α,different adjacent louver baffle group included angle β and different arrangements of heat exchange tubes.The main contents and conclusions are as follows:(1)Compared with the segmental baffle heat exchanger,the fluid flow on the shell side of the staggered louver baffle heat exchanger forms an obvious spiral flow and the overall flow of the shell side has a uniform flow,which effectively reduces the flow dead zone and backflow area,strengthens the flow disturbance behind the baffle,and intensifies the heat transfer in this zone.(2)Researches on the performance of the louver baffle inclination angle α show that the shell side pressure drop of the staggered louver baffle heat exchanger always lower than that of the heat exchanger with segmental baffle,while the angle of inclination of the blade baffle is between 30°～75°,which reduces by 70.66%～79.61% and the reduction rate decreases with the increase of the inclination of the louver baffle.In the same pressure drop,the heat transfer coefficient is higher than that of the heat exchanger with segmental baffle,which increases by 79.49%～118.7%.With the increase of the inclination of the louver baffle,the heat transfer coefficient increases first and then decreases.(3)Researches on the performance of the angle between adjacent louver baffle groups show that while the angle of the louver baffle group is in the range of 15°～75°,the shell side pressure drop of the staggered louver baffle heat exchanger decreases by 67.11%～80.59%,the reduction rate of which decreases with the increase of the included angle.In the same pressure drop,the heat transfer coefficient increases by 88.52%～118.70% and the increase of the angle between adjacent louver baffle groups increases first and then decreases.(4)This article analyzes the effect on the staggered louver baffle heat exchanger when the heat exchange tube bundles are of the square and triangular arrangements.The calculation shows that when the heat exchange tube bundle,the inclination angle of the louver baffle and the angle of the adjacent louver baffle group are the same,the comprehensive performance of the triangularly arranged staggered louvered baffle heat exchanger is better than that of the squarely arranged heat exchange.(5)In the scope of this article,the heat transfer coefficient of the staggered louver baffle heat exchanger per unit pressure drop is higher than that of the segmental baffle heat exchanger,which means that under the same pump power consumption,the staggered louver baffle heat exchanger has better heat exchange performance.It also consumes less pump power while achieving the same heat transfer performance,which is a new type of high-efficiency and energy-saving structure."45-45-△" type staggered louver baffle heat exchanger has the best performance,whose comprehensive performance is 115.00% ～118.70% higher than that of the bow-shaped baffle heat exchanger.