化工进展
化工進展
화공진전
CHEMICAL INDUSTRY AND ENGINEERING PROGRESS
2015年
1期
266-272
,共7页
张一龙%孙美%刘坐东%王景涛%徐志明
張一龍%孫美%劉坐東%王景濤%徐誌明
장일룡%손미%류좌동%왕경도%서지명
纳米颗粒%微米颗粒%结垢%数值模拟%团聚
納米顆粒%微米顆粒%結垢%數值模擬%糰聚
납미과립%미미과립%결구%수치모의%단취
nanoparticles%micro particles%fouling%numerical simulation%agglomeration
目前对颗粒污垢的研究主要局限于实验研究,通过实验和模拟的手段分别对微米和纳米颗粒污垢沉积的内在关系研究较少。为了研究静止流体中纳米级颗粒污垢与微米颗粒污垢出现相似沉积特点的原因,分别在不同工况下进行纳米颗粒污垢和微米颗粒污垢的沉积实验,并应用扫描电镜对试片表面进行观测。通过模拟方式得出不同粒径微米颗粒污垢的沉积质量,由实验得出颗粒污垢沉积质量呈现出渐进增长趋势。随着浓度的增大其渐进沉积质量越来越大,达到渐进污垢沉积量的时间越来越短。由于颗粒间的团聚效应,使纳米颗粒污垢出现与微米颗粒污垢相似的沉积规律。基于这种规律,提出纳米颗粒污垢等效直径的概念。将实验结果与不同直径微米级颗粒沉积模拟结果相结合,得出浓度0.4g/L 的纳米悬浮液团聚后的等效直径约为9.2μm;浓度0.6g/L的纳米颗粒悬浮液团聚后的等效直径约为11.2μm。
目前對顆粒汙垢的研究主要跼限于實驗研究,通過實驗和模擬的手段分彆對微米和納米顆粒汙垢沉積的內在關繫研究較少。為瞭研究靜止流體中納米級顆粒汙垢與微米顆粒汙垢齣現相似沉積特點的原因,分彆在不同工況下進行納米顆粒汙垢和微米顆粒汙垢的沉積實驗,併應用掃描電鏡對試片錶麵進行觀測。通過模擬方式得齣不同粒徑微米顆粒汙垢的沉積質量,由實驗得齣顆粒汙垢沉積質量呈現齣漸進增長趨勢。隨著濃度的增大其漸進沉積質量越來越大,達到漸進汙垢沉積量的時間越來越短。由于顆粒間的糰聚效應,使納米顆粒汙垢齣現與微米顆粒汙垢相似的沉積規律。基于這種規律,提齣納米顆粒汙垢等效直徑的概唸。將實驗結果與不同直徑微米級顆粒沉積模擬結果相結閤,得齣濃度0.4g/L 的納米懸浮液糰聚後的等效直徑約為9.2μm;濃度0.6g/L的納米顆粒懸浮液糰聚後的等效直徑約為11.2μm。
목전대과립오구적연구주요국한우실험연구,통과실험화모의적수단분별대미미화납미과립오구침적적내재관계연구교소。위료연구정지류체중납미급과립오구여미미과립오구출현상사침적특점적원인,분별재불동공황하진행납미과립오구화미미과립오구적침적실험,병응용소묘전경대시편표면진행관측。통과모의방식득출불동립경미미과립오구적침적질량,유실험득출과립오구침적질량정현출점진증장추세。수착농도적증대기점진침적질량월래월대,체도점진오구침적량적시간월래월단。유우과립간적단취효응,사납미과립오구출현여미미과립오구상사적침적규률。기우저충규률,제출납미과립오구등효직경적개념。장실험결과여불동직경미미급과립침적모의결과상결합,득출농도0.4g/L 적납미현부액단취후적등효직경약위9.2μm;농도0.6g/L적납미과립현부액단취후적등효직경약위11.2μm。
Particulate fouling research is mainly done by experiment at present. There are hardly any research on internal relationship between nanometer and micrometer particles fouling through simulation and experiment. There are some similar deposition characteristics between nanoparticle and micro particle fouling. Nanoparticle and micro particle fouling deposition experiments were conducted under different working conditions,and surface characteristics were observed by SEM. The fouling deposition quantity was determined by simulation with different particle sizes. A gradual growth trend of deposition quantity of particles fouling was observed. Due to agglomeration effect,there was similar deposition result between nanoparticles and micro particles fouling. The equivalent diameter was proposed for nanoparticles by combining the nanoparticles experiment and micro particles simulation results. The equivalent diameter was 9.2μm for 0.4g/L nanometer suspensions. The equivalent diameter was 11.2μm for 0.6g/L nanometer suspensions.