Recently, reactivity controlled compression ignition (RCCI) has been proposed inorder to achieve a higher thermal efficiency with lower emissions than conventional combustion. In RCCI mode, as the fuel types and thei...Recently, reactivity controlled compression ignition (RCCI) has been proposed inorder to achieve a higher thermal efficiency with lower emissions than conventional combustion. In RCCI mode, as the fuel types and their combinations affects the reactivity stratificationinside cylinder, thus combustion control, in present study, iso-propanol was evaluated as lowreactivity fuel (LRF) when petroleum diesel, commercial biodiesel and their blends were highreactivity fuels. It is of great importance that iso-propanol and biodiesel be used together inRCCI mode, as they significantly affect the in-cylinder stratification due to their high octane/cetane number. Therefore, the reactivity controlled compression ignition (RCCI) combustioncharacteristics was investigated in a diesel research engine using iso-propanol, petroleumdiesel, biodiesel and their blends as fuels. Tests were conducted on varying loadings (from20% to 60% of max torque) and premixed ratios of LRF (Rp Z 0, 0.15, 0.30, 0.45, and0.60) at a constant engine speed of 2400 rpm. Results, which were compared with conventionaldiesel combustion (CDC), showed that, as the premixed ratio (Rp) of low-reactivity fuel (isopropanol) increased, ignition delay (ID) period prolonged while combustion duration (CD) and rate of pressure rise (RoPR) reduced assisted to reduce NO emissions and smoke opacity in theexhaust. NO and smoke opacity reduced simultaneously for biodiesel-propanol combinationsup to 40% under 20% load and 0.60 premixed ratio of LRF compared to CDC. Propanol premixed ratio of 0.30 at 60% load was found to be optimum concerning lowest emissions. In conventional mode, HC emissions reduced by up to 52% when biodiesel and its blends with dieselfuel are used, whereas they increased significantly in RCCI mode. According to overall results,it is concluded that RCCI performed better than CDC at entire load.展开更多
在总循环能量和发动机转速不变的条件下,运用一台六缸重型增压柴油机研究了不同喷油定时和氧含量对正丙醇/柴油活性控制压燃(Reactivity controlled compression ignition,RCCI)的燃烧与排放特性的影响.结果表明,随着喷油定时(Start of ...在总循环能量和发动机转速不变的条件下,运用一台六缸重型增压柴油机研究了不同喷油定时和氧含量对正丙醇/柴油活性控制压燃(Reactivity controlled compression ignition,RCCI)的燃烧与排放特性的影响.结果表明,随着喷油定时(Start of injection,SOI)的提前,第一燃烧阶段的放热率峰值和缸内温度不断增加,初始着火相位(CA10)和燃烧重心(CA50)同步提前,燃烧持续期基本不变,滞燃期增加.CO和HC的排放随SOI提前逐渐减小,而NO_(x)的排放随SOI提前逐渐增加;颗粒物排放的平均粒径(Particle average diameter,PAD)和颗粒物质量浓度(Particle mass concentration,PMC)及颗粒物数量浓度(Particle number concentration,PNC)会随SOI的提前呈现出逐渐降低的趋势.而氧含量(Oxygen ratios,RO)的增加会使缸内压力和缸内温度整体略微下降,滞燃期整体小幅度增加.CO和HC的排放会随着RO的增加而增加,但RO基本不影响NO_(x)的排放.另外,RO的增加会使得PAD增加,PNC降低,对PMC的影响规律不明显.展开更多
基金The Scientific and Technological Research Council of Turkey(TUBITAK)is greatly acknowledgment for financial support with project numbered 118M650.
文摘Recently, reactivity controlled compression ignition (RCCI) has been proposed inorder to achieve a higher thermal efficiency with lower emissions than conventional combustion. In RCCI mode, as the fuel types and their combinations affects the reactivity stratificationinside cylinder, thus combustion control, in present study, iso-propanol was evaluated as lowreactivity fuel (LRF) when petroleum diesel, commercial biodiesel and their blends were highreactivity fuels. It is of great importance that iso-propanol and biodiesel be used together inRCCI mode, as they significantly affect the in-cylinder stratification due to their high octane/cetane number. Therefore, the reactivity controlled compression ignition (RCCI) combustioncharacteristics was investigated in a diesel research engine using iso-propanol, petroleumdiesel, biodiesel and their blends as fuels. Tests were conducted on varying loadings (from20% to 60% of max torque) and premixed ratios of LRF (Rp Z 0, 0.15, 0.30, 0.45, and0.60) at a constant engine speed of 2400 rpm. Results, which were compared with conventionaldiesel combustion (CDC), showed that, as the premixed ratio (Rp) of low-reactivity fuel (isopropanol) increased, ignition delay (ID) period prolonged while combustion duration (CD) and rate of pressure rise (RoPR) reduced assisted to reduce NO emissions and smoke opacity in theexhaust. NO and smoke opacity reduced simultaneously for biodiesel-propanol combinationsup to 40% under 20% load and 0.60 premixed ratio of LRF compared to CDC. Propanol premixed ratio of 0.30 at 60% load was found to be optimum concerning lowest emissions. In conventional mode, HC emissions reduced by up to 52% when biodiesel and its blends with dieselfuel are used, whereas they increased significantly in RCCI mode. According to overall results,it is concluded that RCCI performed better than CDC at entire load.
文摘在总循环能量和发动机转速不变的条件下,运用一台六缸重型增压柴油机研究了不同喷油定时和氧含量对正丙醇/柴油活性控制压燃(Reactivity controlled compression ignition,RCCI)的燃烧与排放特性的影响.结果表明,随着喷油定时(Start of injection,SOI)的提前,第一燃烧阶段的放热率峰值和缸内温度不断增加,初始着火相位(CA10)和燃烧重心(CA50)同步提前,燃烧持续期基本不变,滞燃期增加.CO和HC的排放随SOI提前逐渐减小,而NO_(x)的排放随SOI提前逐渐增加;颗粒物排放的平均粒径(Particle average diameter,PAD)和颗粒物质量浓度(Particle mass concentration,PMC)及颗粒物数量浓度(Particle number concentration,PNC)会随SOI的提前呈现出逐渐降低的趋势.而氧含量(Oxygen ratios,RO)的增加会使缸内压力和缸内温度整体略微下降,滞燃期整体小幅度增加.CO和HC的排放会随着RO的增加而增加,但RO基本不影响NO_(x)的排放.另外,RO的增加会使得PAD增加,PNC降低,对PMC的影响规律不明显.
