Investigation Of Semi-random Semi-regular Hollow Fiber Membrane-based Humidification Module’s Humidification Performance

With the improvement of people’s living standard,people pay more and more attention on the comfort of indoor environment.Except indoor temperature,the indoor humidity is another important factor which affects the indoor comfort.Under low humidity environment,people feel dry and may get respiratory and skin disease in long time exposure,therefore air humidification is of great importance.In this project,a semi-random and semi-regular hollow fiber membrane module is designed and fabricated.It improves the structure of the conventional hollow fiber membrane module and thus reduce the manufacturing cost and maintenance cost with module’s performance unchanged.Because of large hollow fiber filling density,the air humidification amount is higher than other humidification methods.Except this,hollow fiber membrane-based humidification method prevents liquid drops,so it is a very promising indoor air humidification technology.The major work in this study is as following:(1)According to the requirements of the indoor environment humidity standard,a semi-random,semi-regular hollow fiber membrane humidification module was designed and manufactured by using the self-developed hollow fibers.Blocks in the whole module assembled with random arrangement.Water in the tube is used for humidifying the air which crossly-flow through the fibers.The filling rate of the blocks in the module is 25%.(2)The performance test platform for the semi-random,semi-regular hollow fiber module was designed.The influence of air flow rate,water flow rate and water temperature on the humidification performance and pressure drop of the module is studied.It can be drawn from the experimental and numerical simulation results that the increase of air flow rate improves the humidification and mass transfer coefficient of the module,but the humidification efficiency is reduced and the shell pressure drop increases.When the flow rate is 95m3/h and the water flow is 100L/h,the SHP(specific humidification power),the total mass transfer coefficient,the humidification efficiency are 242.60g/m2 h,0.00652m/s and 43.8%,respectively.The humidification effect is remarkable.The change of the flow rate of water flow imposes little effect on the humidification of the module,so it is suggested to reduce the water flow if the components are filled with water,which has a positive effect on optimizing the module structure and reducing the cost.(3)According to the theoretical model,the simulation on the module is carried out and compared with the experimental results,which verifies the accuracy of the theoretical model.The new type semi-random and semi-regular hollow fiber membrane module is compared with another two conventional modules,and the result shows that the new module has better humidification power.The influence of structural change on the humidification performance and pressure drop is analyzed.The results show that the effect of change of block arrangement is not very obvious in terms of enhancing the humidification performance of the module,however,the pressure drop is obviously increased.Increasing the length of the hollow fiber membrane also leads to reduction of the pressure drop,and enhancement of the humidification effect.Through the above analysis,the guidance for optimizing the structure and performance of module is provided.