农业工程学报
農業工程學報
농업공정학보
2014年
9期
42-49
,共8页
陈朝辉%张韦%陈贵升%沈颖刚
陳朝輝%張韋%陳貴升%瀋穎剛
진조휘%장위%진귀승%침영강
柴油机%催化器%温度%排放%基底特性%氮氧化物%碳烟
柴油機%催化器%溫度%排放%基底特性%氮氧化物%碳煙
시유궤%최화기%온도%배방%기저특성%담양화물%탄연
diesel%catalytic%temperature%exhaust%substrate property%NOx%soot
为了提高催化器CDPF（catalyzed diesel particulate filter）去除NOx和PM的性能，该文运用催化试验、发动机台架试验及模拟计算，研究了排气温度和催化器的基底材料特性对NOx还原和PM氧化的影响特性。通过活性评价和表征试验发现，由于La2Cu0.7Fe0.3O4表面具有较高的氧空位浓度和较强的晶格氧移动特性，所以300°C~500°C时具有较好的催化活性，且350°C~500°C时碳化硅较堇青石能更好地催化还原NO。发动机台架试验表明，由于碳化硅具有更高的孔隙率和更好的热交换特性，在1600 r/min的75%和90%负荷工况时，碳化硅CDPF具有更好地催化去除NOx和PM的特性规律。模拟计算结果显示，具有较高过滤孔密度和比表面积的CDPF，由于较低的内部传质阻力和较高的传质特性，所以能较好地还原NOx和氧化PM。研究结果可为优化柴油机后处理器CDPF的催化性能提供科学依据。
為瞭提高催化器CDPF（catalyzed diesel particulate filter）去除NOx和PM的性能，該文運用催化試驗、髮動機檯架試驗及模擬計算，研究瞭排氣溫度和催化器的基底材料特性對NOx還原和PM氧化的影響特性。通過活性評價和錶徵試驗髮現，由于La2Cu0.7Fe0.3O4錶麵具有較高的氧空位濃度和較彊的晶格氧移動特性，所以300°C~500°C時具有較好的催化活性，且350°C~500°C時碳化硅較堇青石能更好地催化還原NO。髮動機檯架試驗錶明，由于碳化硅具有更高的孔隙率和更好的熱交換特性，在1600 r/min的75%和90%負荷工況時，碳化硅CDPF具有更好地催化去除NOx和PM的特性規律。模擬計算結果顯示，具有較高過濾孔密度和比錶麵積的CDPF，由于較低的內部傳質阻力和較高的傳質特性，所以能較好地還原NOx和氧化PM。研究結果可為優化柴油機後處理器CDPF的催化性能提供科學依據。
위료제고최화기CDPF（catalyzed diesel particulate filter）거제NOx화PM적성능，해문운용최화시험、발동궤태가시험급모의계산，연구료배기온도화최화기적기저재료특성대NOx환원화PM양화적영향특성。통과활성평개화표정시험발현，유우La2Cu0.7Fe0.3O4표면구유교고적양공위농도화교강적정격양이동특성，소이300°C~500°C시구유교호적최화활성，차350°C~500°C시탄화규교근청석능경호지최화환원NO。발동궤태가시험표명，유우탄화규구유경고적공극솔화경호적열교환특성，재1600 r/min적75%화90%부하공황시，탄화규CDPF구유경호지최화거제NOx화PM적특성규률。모의계산결과현시，구유교고과려공밀도화비표면적적CDPF，유우교저적내부전질조력화교고적전질특성，소이능교호지환원NOx화양화PM。연구결과가위우화시유궤후처리기CDPF적최화성능제공과학의거。
The influence of different temperatures and CDPF (catalyzed diesel particulate filter) substrate properties on NOx reduction and PM oxidation were studied by catalytic experiments, engine bench tests and simulation. From activity evaluation and characterization tests, it was found that owing to the higher mobility of lattice oxygen and the maximum concentrations of oxygen vacancies, La2Cu0.7Fe0.3O4 showed a relatively better catalytic performance between 300°C to 500°C. The NO conversion efficiency on SiC (Silicon carbide) substrate was better than that on cordierite substrate from 350℃ to 500℃ under simulated diesel emission conditions. The engine bench test results showed that NOx conversion efficiency increased from 340℃ to 528℃. Due to higher porosity and stronger thermal diffusion characteristics, the soot oxidation rate and NOx conversion rate on SiC substrate CDPF is better than that on cordierite substrate, under condition of 75%and 90%loads of engine at 1 600 r/min. From simulation researches, CDPF with higher cell density and specific surface-area cell resulted in lower internal mass-transfer resistances, and higher mass-transfer coefficients, which yielded better soot and NOx reduction performances.
