VNT对柴油机NO_x排放特性优化的研究

发布时间：2018-05-19 02:37

本文选题：内燃机 + 柴油机　；参考：《内燃机工程》2016年06期

【摘要】：为了研究可变喷嘴涡轮(VNT)技术对降低柴油机NO_x排放的作用,首先对带排气旁通阀涡轮增压器(WG)和文丘里管高压废气再循环(vEGR)的WG-vEGR涡轮增压柴油机原机,运用GT-Power软件和AVL FIRE软件进行VNT的匹配,对柴油机综合性能进行了仿真计算,确定欧洲稳态测试循环(ESC)工况最优VNT开度规律,组成VNT-vEGR柴油机。随后对WG-vEGR柴油机和VNT-vEGR柴油机进行了ESC工况台架试验研究。研究结果表明:VNT能够提高柴油机的废气再循环(EGR)率,VNT-vEGR柴油机的ESC工况加权NO_x排放值为3.53g/(kW·h),与WG-vEGR柴油机原机的4.92g/(kW·h)相比,下降约28.25%;ESC工况加权比油耗为232.1g/(kW·h),相比于WG-vEGR柴油机原机的235.5g/(kW·h),降低约1.44%;ESC工况加权碳烟排放值为0.055g/(kW·h),相比于WG-vEGR柴油机原机的0.058g/(kW·h),降低约5.17%。且从加权比油耗和碳烟排放值的变化情况可以看出,该系统具有采用更大EGR率以获得NO_x排放进一步优化的潜力。
[Abstract]:In order to study the effect of variable nozzle turbine (VNT) technology on reducing NO_x emission of diesel engine, the original engine of WG-vEGR turbocharged diesel engine with exhaust bypass valve turbocharger (WGG) and Venturi tube high pressure exhaust gas recirculation (VEGR) was first studied. By using GT-Power and AVL FIRE software to match VNT, the comprehensive performance of diesel engine is simulated and calculated, and the optimal VNT opening law of European steady-state test cycle is determined. The VNT-vEGR diesel engine is composed of VNT-vEGR diesel engine. Then the WG-vEGR diesel engine and the VNT-vEGR diesel engine were tested on the bench under the ESC condition. The results show that the weight NO_x emission value of VNT-vEGR diesel engine under ESC condition is 3.53g/(kW hu, which is higher than that of WG-vEGR diesel engine, compared with that of WG-vEGR diesel engine, which can increase the exhaust gas recirculation rate of VNT-VEGR diesel engine and the weighted NO_x emission value of VNT-vEGR diesel engine. Compared with the original WG-vEGR diesel engine, the fuel consumption is reduced by 28.25%, compared with that of the original WG-vEGR diesel engine, the weighted soot emission value is about 1.44% 0.055g/(kW hu, and 5.17% lower than that of the WG-vEGR diesel engine. It can be seen from the change of fuel consumption and soot emission value of weighted ratio that the system has the potential to adopt larger EGR rate to obtain further optimization of NO_x emissions.
【作者单位】：同济大学汽车学院;
【基金】：国家自然科学基金项目(51106114) 教育部高等学校博士学科点专项科研基金项目(20110072120002)
【分类号】：TK421.5

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