简介：随着全球经济快速发展以及居民生活水平的提高,城市生活垃圾的产量日益增加,垃圾处理己成为限制城市化进程和城市经济发展的重大问题之一.本文综述了城市生活垃圾的物理组成分类以及特性和成分分析,总结讨论了目前生活垃圾主要的厌氧消化技术进展,并对城市生活垃圾厌氧消化技术中干/湿厌氧消化、单相/两相厌氧消化、连续/批式厌氧消化、常/高温厌氧消化等工艺进行了详细说明,以及阐述有机负荷、pH值温度等因素对厌氧消化效果的影响,做出对生活垃圾厌氧消化技术的研究展望,为研究城市生活垃圾厌氧消化技术研究提供理论基础.

简介：Severalindustrialapplicationssuchaselectronicdevices,heatexchangers,gasturbineblades,etc.needcoolingprocesses.Theinternalcoolingtechniqueisproperforsomeapplications.Inthepresentwork,computationalsimulationsweremadeusingANSYSCFXtopredicttheimprovementsofinternalheattransferintherectangularribbedchannelusingdifferentcoolants.Severalcoolantssuchasair,steam,air/mistandsteam/mistwereinvestigated.Theshearstresstransportmodel(SST)isselectedbycomparingthestandardk-ωandOmegaReynoldsStress(ωRS)turbulencemodelswithexperimentalresults.Theresultsindicatethattheheattransfercoefficientsareenhancedintheribbedchannelwhileinjectingsmallamountsofmist.Theheattransfercoefficientsofair/mist,steamandsteam/mistincreaseby12.5%,49.5%and107%overthatofair,respectively.Furthermore,incomparisontoair,theair/mistheattransfercoefficientenhancesbyabout1.05to1.14timeswhenthemistmassfractionincreasesfrom2%to8%,respectively.Thesteam/mistheattransfercoefficientincreasesbyabout1.12to1.27timeshigherthanthatofsteamovertheconsideredrangeofmistmassfraction.