柴油机
柴油機
시유궤
DIESEL ENGINE
2012年
4期
1-5
,共5页
耿壮壮%吕兴才%广环宇%杨铮%黄震
耿壯壯%呂興纔%廣環宇%楊錚%黃震
경장장%려흥재%엄배우%양쟁%황진
HCCI燃烧%HC%分布%边界层
HCCI燃燒%HC%分佈%邊界層
HCCI연소%HC%분포%변계층
Homogenous Charge Compression Ignition (HCCI) combustion%HC%distribution%boundarylayer
试验研究了均质充量压缩着火(HCCI)燃烧过程中边界层区域HC生成、分布与消耗历程,考察了边界层各个区域对整体HC排放的贡献比例。为此,在快速压缩机上利用瞬态HC排放仪测量了均质混合气在当量比0.4、不同压缩比下靠近气缸盖底面和气缸体侧面不同距离的各测点在全反应历程内的HC浓度。研究发现:压缩比降低使得边界层效应更加明显;同一工况下,气缸盖底面和气缸体侧面的边界层厚度因受到压缩挤流和壁面传热的影响而不同,气缸体侧面的边界层效应比气缸盖底面的更加显著;靠近气缸盖底面和气缸体侧面2mm以内的区域对整体HC排放的贡献较高,气缸中心燃烧核心区域贡献较小。
試驗研究瞭均質充量壓縮著火(HCCI)燃燒過程中邊界層區域HC生成、分佈與消耗歷程,攷察瞭邊界層各箇區域對整體HC排放的貢獻比例。為此,在快速壓縮機上利用瞬態HC排放儀測量瞭均質混閤氣在噹量比0.4、不同壓縮比下靠近氣缸蓋底麵和氣缸體側麵不同距離的各測點在全反應歷程內的HC濃度。研究髮現:壓縮比降低使得邊界層效應更加明顯;同一工況下,氣缸蓋底麵和氣缸體側麵的邊界層厚度因受到壓縮擠流和壁麵傳熱的影響而不同,氣缸體側麵的邊界層效應比氣缸蓋底麵的更加顯著;靠近氣缸蓋底麵和氣缸體側麵2mm以內的區域對整體HC排放的貢獻較高,氣缸中心燃燒覈心區域貢獻較小。
시험연구료균질충량압축착화(HCCI)연소과정중변계층구역HC생성、분포여소모역정,고찰료변계층각개구역대정체HC배방적공헌비례。위차,재쾌속압축궤상이용순태HC배방의측량료균질혼합기재당량비0.4、불동압축비하고근기항개저면화기항체측면불동거리적각측점재전반응역정내적HC농도。연구발현:압축비강저사득변계층효응경가명현;동일공황하,기항개저면화기항체측면적변계층후도인수도압축제류화벽면전열적영향이불동,기항체측면적변계층효응비기항개저면적경가현저;고근기항개저면화기항체측면2mm이내적구역대정체HC배방적공헌교고,기항중심연소핵심구역공헌교소。
Experimental study was carried out on HC sources, distribution and consumption of HCCI combustion, and also on HC contributions of different regions of boundary layer. These experiments were conducted on an RCM using a fast response HC detector to measure the HC concentrations of different re gions near the cylinder head and the cylinder liner during the combustion process with the equivalent ratio of 0.4 and different compression ratios. Experimental results show that: decrease of compression ratio makes the boundary layer contributions bigger; under the same compression ratio, the thickness of the boundary layer near the cylinder head and the cylinder liner is different because of the influences of the swirl flow and the wall heat transfer, the boundary layer effects of the region near the cylinder liner are more obvious than those of the region near the cylinder head ; the HC contribution of the regions near both the cylinder head and the cylinder liner with thickness under 2mm is bigger, while the HC contribution of the core combustion region around the cylinder centerline is smaller.