| The world energy crisis has promoted the development of enhanced heat-transfer technology, in order to reduce the energy consumption, developing efficient heat transmission equipment for different industrial requirements is what we need to do. Because tubular falling film evaporator has the advantages of high heat transfer efficiency, small heat transfer temperature differences etc, it has been used in many industrial fields, and the study of tubular falling film evaporator has become an important subject of heat-transfer technology in recent years.In this paper, a set of tubular falling film evaporation equipment is designed, a type of industrial devices lignin suspending liquid is used to do the experiment as a working fluid. The heat transfer characteristic is studied. The impact of spraying liquid density,temperature differences,the solid content and heat flux on the evaporation heat transfer coefficient is obtained.The performance of the sieve distributor designed is tested through the experiment on the condition of cold membrane. The results is obtained through the heat transfer experiment:When the spray density in the rang ofΓ=0.1 kg/m-s-0.4 kg/m·s, the evaporative heat transfer coefficient in the tubes and the total heat transfer coefficient were increased along with the increase of the spray density; On the definite spray density,evaporative heat transfer temperature difference increase within a certain range, the evaporation side of heat transfer coefficient increases, when heat transfer temperature difference is increase, the total heat transfer coefficient has an increasing trend;Solid content of lignin suspending liquid have great influence on the evaporation side heat transfer coefficient,with the increase of the content solid, heat transfer coefficient on the evaporation side is decrease, and with the increase of heat flux, heat transfer coefficient on the evaporation side is increase. In this paper, the experimental data of the solid content for 16.5% is processed and an empirical formula is obtained, it can be used in some certain conditions and the errors in less than 10%. |
