柴油机设计与制造
柴油機設計與製造
시유궤설계여제조
DESIGN & MANUFACTURE OF DIESEL ENGINE
2015年
2期
16-19,40
,共5页
柴油机%氮氧化物%选择性催化还原%转化率
柴油機%氮氧化物%選擇性催化還原%轉化率
시유궤%담양화물%선택성최화환원%전화솔
diesel engine%nitrogen oxides%selective catalytic reduction%conversion rate
概述了尿素选择性催化还原(Urea- SCR)技术的机理及其基本化学反应。在发动机台架试验的基础上,应用数值计算软件,针对发动机不同工况进行了数值计算,详细分析研究了氨氮比、排气温度及空速对催化转化效率的影响。通过数值计算,得出氨氮比的变化对氮氧化物(NOx)转化效率的影响规律,可快速确定柴油机指定工况下的NOx最大转化效率,将氨泄漏量控制在最低范围内;随着排气温度升高,NOx转化效率呈先升高后下降的趋势;随着空速的增大,转化效率有所降低,且变化程度随着排温的变化而有所不同。。
概述瞭尿素選擇性催化還原(Urea- SCR)技術的機理及其基本化學反應。在髮動機檯架試驗的基礎上,應用數值計算軟件,針對髮動機不同工況進行瞭數值計算,詳細分析研究瞭氨氮比、排氣溫度及空速對催化轉化效率的影響。通過數值計算,得齣氨氮比的變化對氮氧化物(NOx)轉化效率的影響規律,可快速確定柴油機指定工況下的NOx最大轉化效率,將氨洩漏量控製在最低範圍內;隨著排氣溫度升高,NOx轉化效率呈先升高後下降的趨勢;隨著空速的增大,轉化效率有所降低,且變化程度隨著排溫的變化而有所不同。。
개술료뇨소선택성최화환원(Urea- SCR)기술적궤리급기기본화학반응。재발동궤태가시험적기출상,응용수치계산연건,침대발동궤불동공황진행료수치계산,상세분석연구료안담비、배기온도급공속대최화전화효솔적영향。통과수치계산,득출안담비적변화대담양화물(NOx)전화효솔적영향규률,가쾌속학정시유궤지정공황하적NOx최대전화효솔,장안설루량공제재최저범위내;수착배기온도승고,NOx전화효솔정선승고후하강적추세;수착공속적증대,전화효솔유소강저,차변화정도수착배온적변화이유소불동。。
This paper provides an overview of the mechanism of urea selective catalytic reduction (Urea-SCR) technology and the basic chemical reactions. Based on bench test, numerical calculation in different engine operating conditions is carried out. The effect of exhaust temperature, ammonia ratio and space velocity on conversion efficiency is studied through numerical simulation software. With the numerical calculation, the effect of ammonia ratio on de-NOx rate is obtained, with which the maximum conversion rate in specified conditions of diesel engine can be quickly determined to control the ammonia leakage in the lowest range. NOx conversion rate increases at first and then declines with exhaust temperature rising. The conversion efficiency reduces with the increase of space velocity and changes with exhaust temperature.