微液滴与薄液膜耦合强化低浓度H2S热质传递的机理研究
批准号:
52106123
项目类别:
青年科学基金项目(C类)
资助金额:
30.0 万元
负责人:
郑毅
依托单位:
学科分类:
传热传质学
结题年份:
2024
批准年份:
2021
项目状态:
已结题
项目参与者:
郑毅
中文摘要
在工业生产过程中硫化氢泄漏事故频发,对人民生命安全构成巨大的威胁,泄漏到环境中的硫化氢气体浓度低,且含有的大量不吸收气抑制了硫化氢与吸收液的有效接触和界面传递,降低吸收效率。传统吸收过程中,液膜厚度大,气相扰动弱,因此开发既促进气相扰动又降低液相传质阻力的新型强化技术,是实现低浓度硫化氢高效吸收的有效手段。本项目基于喷淋降落微液滴促进气相主体扰动和结构超亲水表面周期性波动薄液膜高效传质,提出了微液滴与薄液膜耦合强化低浓度硫化氢低流量吸收的新思路。主要研究微液滴的空间行为与特征参数对气相主体扰动和低浓度硫化氢界面传递特性的影响,分析结构超亲水表面周期性波动的薄液膜与低浓度硫化氢气体间的热质传递规律,探究周期性波动薄液膜促进气液界面更新和液膜内部微细传递规律的物理本质,获得低流量下微液滴扰动与薄液膜波动促进低浓度硫化氢吸收的调控策略,为高效紧凑应急吸收装备的研发提供理论支持。
英文摘要
In the process of industrial production, the accidents of hydrogen sulfide leakage frequently occur, posing a huge threat to the safety of people. The concentration of hydrogen sulfide leaked into the environment is low and contained lots of non-absorbable gas, which inhibits the effective contact and interface transfer between hydrogen sulfide and absorption liquid and signification reduce mass transfer performance. For traditional absorption process, the liquid film is thick and the gas phase disturbance is weak, which offer a poor mass transfer performance. So, the development of a new enhances technology that not only promotes the gas phase disturbance but also reduces liquid phase mass transfer resistance is an effective means to enhance the absorption of low concentration hydrogen sulfide. Based on promote gas phase main body disturbance and absorption by spray micro-droplets and efficient mass transfer of thin film with periodic fluctuation on structure superhydrophilic surface, a new idea for coupling of mico-droplet and thin film to enhance the masstransfer of low concentration hydrogen sulfide is proposed. The main research is to study the influence of the effect of spatial behavior and feature parameters of micro droplet on the gas body disturbance and interface transfer characteristics of low concentration hydrogen sulfide. The heat and mass transfer evolution regular between periodic fluctuation thin film and low concentration hydrogen sulfide on structure superhydrophilic surface are also being analyzed. After that, the effect of periodic fluctuation of liquid film on gas-liquid interface renewal and the physical essence of mass transfer performance are systematic study. Further, the control strategy of micro-droplet disturbance and thin film fluctuation at low flow rate absorbs low concentration hydrogen sulfide is proposed, which provide theoretical support for the research and development of efficient absorption equipment.
在工业生产过程中H₂S泄漏事故频发,对人民生命安全构成巨大的威胁,泄漏到环境中的H₂S气体浓度低,且含有的大量不吸收气抑制了H₂S与吸收液的有效接触和界面传递,影响吸收效率。本项目基于喷淋降落微液滴促进气相主体扰动和超亲水表面周期性波动薄液膜高效传质,提出了微液滴与薄液膜耦合强化低浓度H₂S低流量吸收的新思路。项目深度探究了微液滴的尺寸效应与空间行为对气相主体扰动和低浓度 H₂S 界面传递的影响,发现微液滴的迎风侧更易产生界面涡旋,促进介质均匀分布,贡献了吸收效能的80%,微液滴尺寸下降10倍传质效率可提升55倍。插排结构的薄液膜分布更有利于边界层的快速分离强化吸收。形成了自脱离微液滴尺寸调控策略,在不降低吸收液流量情形下,液滴平均直径由1000 μm降至50-200 μm。阐明了全过程薄液膜拓扑演变规律与运动特征,薄液膜初始厚度是影响薄液膜运动的最关键因素,其束缚了液膜横向的大尺寸运动,诱发了液膜铺展的“钉扎”效应,且效应区间仅为120~480 μm。明晰了离散薄液膜内部速度与膜厚演变规律,薄液膜的速度分布呈现典型的分区特性,非撞击区,液膜的运动基本停滞,撞击区,液膜速度先增大后减小,在50~60 ms,液膜运动到最大。喷淋密度对液膜速度的增加是通过减小液滴撞击频率,而非增加单个液滴撞击的平均速度。在撞击区,液膜厚度先迅速增加,后逐渐降低,波动剧烈,100ms内由2000 μm降低至200 μm。此后,撞击区上半周液膜逐渐变薄,下部周液膜变化不明显,液膜厚度稳定在100~150μm。首次发现了薄液膜的空间传递周期规律,撞击形成的二次液滴产生的间距为泰勒-瑞利波长的整数倍,并建立数学模型对周期性演变规律和离散液膜厚度进行预测,膜厚精度较Nusselt模型提升20%。形成了微液滴与薄液膜热质强化低浓度毒害气体吸收的全局优化理念,吸收液用量降低 82%,建立中试尺寸实验平台,处理浓度>8000mg/m3,并在普光气田开展现场应用,吸收率>95%,为应急装备的高效化与集成化提供技术支撑。
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